Echo User Manual

01Getting Started

What Echo plays

Echo is a player for DRM-free audiobooks — files you own and can see in the Files app:

• MP3 / M4A — including folders of one-file-per-chapter rips
• M4B — with full embedded chapter parsing, including books split across multiple M4B files (chapters are aggregated automatically)
• FLAC, AAC, AIFF, OGG, OPUS, WMA — on Mac
• EPUB — as a synced companion text (see The Reader)
• PDF — as a synced companion document (see PDF Companions)

Echo does not bypass DRM and cannot play protected Audible/Apple Books titles. Tools like Libation or OpenAudible can export books you own to open formats — see the FAQ for details and a note on legality.

Loading your first book

1. Put the audiobook in a folder — one folder per book is the happy path (the organization guide has the full convention). iCloud Drive, "On My iPhone," third-party file providers: all work.
2. In Echo, choose Load Folder and select the book's folder.
3. Echo scans the folder, builds the chapter list, finds the cover art (embedded art, or a cover.* image in the folder), and picks up any EPUB or PDF sitting alongside the audio for automatic import.
4. Press play.

Echo remembers everything per book: position, speed, loop mode, and settings overrides. Reopen the app days later and it resumes exactly where you left off — with Smart Rewind backing up just enough to restore your context.

First launch walks you through this — including a step on setting up your library folder 🚧 Coming in 1.0.

Cover art

Echo looks for artwork in this order: image embedded in the audio file → an image file in the book folder (prefers cover.*) → the Echo app icon as fallback. Artwork drives the player background, the watch complication thumbnail, and the dynamic accent color (see Appearance).

02Organizing Your Library

Echo reads your files in place — there's no import-everything step and no hidden copy of your library. That means a little folder discipline up front pays off every single day. Here's the convention Echo is designed around.

The golden rule: one folder per book

iCloud Drive/
└── Audiobooks/
    ├── Thinking, Fast and Slow/
    │   ├── Thinking Fast and Slow.m4b
    │   ├── Thinking Fast and Slow.epub   ← auto-imported
    │   └── cover.jpg                     ← optional if art is embedded
    ├── Project Hail Mary/
    │   ├── 01 - Chapter 1.mp3
    │   ├── 02 - Chapter 2.mp3
    │   ├── …
    │   └── cover.png
    └── Archive/
        └── (finished books)

• One parent folder ("Audiobooks") holds everything. One place to look, one place to back up, one place to point Echo at.
• One folder per book, named by the book title. The folder name is what you'll see and search for — keep it human ("Project Hail Mary", not "PHM_64kbps_final2").
• Companion text goes in the same folder. Drop the .epub or .pdf next to the audio and Echo's auto-import scanner picks it up — no extra steps. One EPUB per book folder.
• An Archive/ subfolder keeps finished books out of your active view without deleting anything. Export your study notes first (see Exports).

File naming that sorts correctly

• Zero-pad track numbers: 01, 02 … 10, 11 — not 1, 2 … 10. Plain alphabetical sorting puts "10" before "2"; zero-padding fixes it everywhere, forever. (You can drag-reorder in Echo's playlist, but correct names mean you never have to.)
• Rename before the first load, not after. Echo tracks progress per file; renaming files mid-book can orphan your position in them.
• Prefer M4B when you have the choice. A single M4B carries embedded chapter markers and cover art inside one tidy file — chapters appear instantly with proper names. Books split across several M4Bs are fine too: Echo aggregates the chapters automatically. Folders of MP3s work well; their "chapters" are just the files, named by you.
• Libation-style fine-grained chapters are handled. Files named like "Chapter 11. A" / "Chapter 11. B" are automatically grouped into logical chapters with sections — see Sections.

iCloud Drive: the rules of the road

• Check the cloud icons before you leave Wi-Fi. A cloud-with-arrow icon next to a file means it's not on the device. Tap to download, or rely on Keep Downloaded.
• iCloud Drive is the cross-device choice: the same folder is reachable from iPhone, iPad, and Mac, so one copy of the library serves every device. "On My iPhone" is the fully-offline choice — always local, never evicted, but invisible to your other devices.
• On the Mac, System Settings → Apple ID → iCloud → "Optimize Mac Storage" does the same eviction trick — right-click the folder in Finder and choose Keep Downloaded there too.
• Third-party providers (Dropbox, Drive, NAS apps) work through the Files app, but many don't support background downloading as smoothly — for daily listening, iCloud Drive or on-device storage is less fussy.
• Don't move or rename the book's folder casually. Echo holds a secure reference to the folder you picked; renaming/moving it may require re-selecting the folder (your bookmarks and cards survive — they live in Echo's database, not the folder).

What lives where

03The Three Tabs

A mini-player bar stays visible on the Timeline tab so transport controls are never more than one tap away.

04Playback

Transport controls

The Now Playing tab gives you five configurable transport buttons. Defaults: skip back, previous chapter, play/pause, next chapter, skip forward.

• Skip durations are configurable from 5–60 seconds, independently for forward and backward, and sync to the watch.
• Long-press secondary actions: each of the five buttons can carry a second action on long-press (e.g., long-press skip-forward for next chapter). Configure under Settings → Player Controls.
• Sections: books with fine-grained chapter files (e.g., "Chapter 11. A", "Chapter 11. B") are automatically grouped into logical chapters. Next/Previous Section actions jump between the sub-sections; the scrubber shows a tick mark at each boundary and snaps to them with a haptic tap while dragging.
• Mark for a flashcard 🚧 Coming in 1.0 — a one-tap Mark action drops the passage into your Card Inbox without pausing playback.

Speed control — pitch-corrected

Echo plays from 0.5× to 2×+ with true pitch correction — voices stay natural at any speed (no chipmunks at 1.25×, no slow-motion growl at 0.8×).

• Set a global default speed in Settings.
• Each book remembers its own speed — your dense textbook can live at 1× while your familiar re-listen runs 1.5×.
• All displayed times (elapsed, remaining, chapter lengths) adjust to your current speed, so "20 minutes left" means real minutes.

Volume boost

Quiet narrator? Enable Volume Boost for up to +9 dB of clean gain (configurable). Works independently of system volume.

Audio behavior

• Playback pauses automatically when your headphones disconnect or the aux cable is pulled — no broadcasting to the room.
• Calls, alarms, and Siri interruptions pause playback and resume correctly afterward (and Echo won't auto-resume if you had paused first).
• Audio is configured as spoken-word audio system-wide, which improves routing and voice processing on every output.

05Smart Rewind

Every time you press play after a pause, Echo rewinds first — proportionally to how long you were gone:

All three tiers are configurable under Settings → Smart Rewind. The rewind happens silently and automatically; you just press play and the story makes sense again.

This is Echo's signature feature: it makes interruption free. You never scrub backward hunting for the last sentence you remember.

06Loop Modes

Echo's loop button cycles through:

• Loop chapter — repeat the current chapter until you turn it off. The feature Echo was built for: loop one chapter all day until you know it.
• Loop playlist — repeat the whole book/playlist.
• Loop between bookmarks — repeat the passage between consecutive bookmarks: drop one bookmark at the start of a key argument, one at the end, and drill exactly that stretch.
• Off — straight through.

Loop mode is remembered per book and is available on the watch and as a transport long-press action.

07Sleep Timer

Set a countdown (with fade-out) or stop at chapter end. When it fires, Echo pauses — and notes the pause time, so tomorrow's Smart Rewind backs you up over whatever you drifted through. Start, stop, and toggle the sleep timer from the phone or directly from the watch.

08Bookmarks

Bookmarks are Echo's capture tool — and they can carry far more than a timestamp.

Creating bookmarks

• Phone: tap the bookmark button in the player (or a configured transport long-press).
• Reader: long-press any paragraph → Save Bookmark (the bookmark binds to that text and its audio moment).
• Watch: one (configurable) button on the remote. A quick-bookmark timeout lets you confirm or auto-save.
• Siri: dictate a bookmark hands-free — the note arrives transcribed.
• PDF: long-press a page → bookmark with a screenshot of that page attached.

What a bookmark can hold

Voice memos that play inline

With Inline Voice Memos enabled, when playback reaches a bookmark that has a memo, Echo ducks the narration and plays your voice — past-you annotating the book for present-you — then resumes the narrator. Toggle globally or per book.

Photo bookmarks & dynamic artwork

Attach a photo to a bookmark and Echo makes it part of the listening experience: as playback passes the bookmark, the player artwork switches to your photo (and back to the cover afterward) — on the phone, the watch, and the lock screen. Your photos become visual mileposts inside the book.

Why bother? Because your brain involuntarily memorizes where you were alongside what you heard — and a photo of the place re-triggers the passage. The full story is in the learning guide.

Managing bookmarks

• Bookmarks group under their book in the playlist, sortable and editable (rename, retime, re-record, swap photo).
• Loop between bookmarks uses them as loop fences (see Loop Modes).
• Export to Markdown: share or archive a book's bookmarks — timestamps, notes, and deep links that reopen Echo at the exact second (see Exports).
• Every bookmark can be promoted to a flashcard in one tap (see next section).

09The Study System (Flashcards & Review)

Echo includes a complete spaced-repetition system (SRS) — think Anki, built into your audiobook player, with audio on the cards. (New to spaced repetition? The learning guide explains it from zero.)

Creating cards

• From the reader: long-press a passage → Create Flashcard. The passage text seeds the card.
• From a bookmark: any bookmark — note, voice memo, photo and all — becomes a card.
• From a mark 🚧 Coming in 1.0 — via the Card Inbox, below.
• From a note 🚧 Coming in 1.0 — promote a Brain Dump entry into a card.
• From scratch: in the Timeline tab.
• Import a deck: Anki-style JSON decks import with validation today; real .apkg files arrive with 1.0 (below).

Every card has a front (your prompt — write it as a question) and a back (the answer), and can carry:

• an audio snippet — the actual narrated clip from the book,
• a photo — e.g., the one from its source bookmark,
• a deck and tags 🚧 Coming in 1.0 — for organizing and filtering,
• a trigger timing — play this card before or after its audio moment during listening, or keep it manual-review-only.

The Card Inbox — mark now, card later 🚧 Coming in 1.0

The flow designed for not interrupting yourself:

1. Mark: one tap on the transport bar (or a watch button) captures the passage you just heard — a few seconds of context either side, with the transcript snippet when the book is aligned. Playback never stops.
2. Inbox: marks collect in the Card Inbox, grouped by book, with a badge on the dashboard and Timeline toolbar.
3. Convert: tap a mark to open the card editor pre-filled — adjust the clip range, write the front as a question, pick a deck, save. Or swipe to dismiss marks that didn't age well.

When the Card Inbox arrives, the old inline flashcard popups retire with honor — capture stops competing with listening. Cards you create default to manual-review-only.

Inline recall during playback

Cards with a trigger timing surface as you listen: reach the moment in the book and Echo quizzes you on the related card — a micro-review in context. Cards set to manual only never interrupt playback. (With 1.0's Card Inbox, new cards default to manual-only and the popup mechanism is retired — your review then lives entirely in Daily Review.)

Editing cards 🚧 Coming in 1.0

Every card opens in a full editor: front and back text, the audio snippet range (with "use current position"), deck, tags, enabled toggle, and delete-with-confirmation. Edit from the Timeline, from a review session's toolbar, or from the deck browser.

Decks & tags 🚧 Coming in 1.0

• Deck list: every deck with its card count and due count; cards without a deck live in an implicit "Unfiled" group.
• Deck detail: searchable card list, per-deck mini-stats, rename, and delete (choose: cascade cards or orphan them to Unfiled).
• Review by deck: "Review this deck" runs a session over just that deck's due cards — exam-week mode.
• Tags: space-separated, Anki-convention tags on every card for cross-deck filtering.

Importing real Anki decks (.apkg) 🚧 Coming in 1.0

Bring your existing Anki collection: pick a .apkg file from the deck list's import button and Echo maps it card-by-card, scheduling history included — mature cards stay mature; nothing restarts from zero.

• What maps: first field → front, remaining fields → back (HTML cleaned to text); tags; suspended cards arrive disabled; referenced images and audio are copied in; review state maps conservatively onto Echo's scheduler.
• Cloze cards are flattened to plain question/answer in v1 (the import summary counts how many, so you can review them).
• Newest Anki format note: if the file uses the newest internal format, Echo will ask you to re-export from Anki with "Support older Anki versions" checked — one checkbox, same cards.
• Imported decks aren't tied to any audiobook (no timestamps) and review like any other cards.

Daily Review

• Echo schedules every card with the SM-2 algorithm (the same scheduling family Anki uses): grade a card and its next appearance is computed from your history — tomorrow if you missed it, weeks out if it was easy.
• The review queue shows everything due today. Grade each card Again / Hard / Good / Easy.
• Cards with audio play their snippet — review with your ears.
• Stats: due count, reviewed-today, and total cards show on the Timeline tab's review module — and the full picture lives in Insights 🚧.
• Notifications: an optional daily local notification reminds you when cards are due. (Local = generated on your device; Echo has no servers.)

Review on Apple Watch

The full review session runs hands-free on the watch: hear the card, think your answer, tap a grade. Perfect for the walk between mailboxes.

10Brain Dump & Book Notes 🚧 Coming in 1.0

Bookmarks pin thoughts to a moment; flashcards pin them to a question. Book Notes are for everything else — thoughts about the book as a whole, tangents worth keeping, and the "buy stamps" intrusions that would otherwise cost you a chapter. The learning guide explains the science; here's the mechanics.

Capturing

• Phone: the Note button in the Now Playing overflow opens a text field — or hold it to record a voice memo. Playback continues underneath.
• Watch: a Dictate Note action on the remote — speak, done. The note lands on the current book without the phone leaving your pocket.
• Notes are untethered — they belong to the book, not a timestamp. (Echo quietly records where you were in the book anyway, as silent context.)

The Notes inbox

• Each book has a Book Notes view — newest first, text and voice entries together, inline playback for memos, swipe to delete.
• Promote any note: → bookmark (pinned at its capture position) or → flashcard (opens the card editor pre-filled). Promotion is how a brain-dump entry graduates once you have bandwidth.
• Entry points: a note icon (with count) on the book's Timeline toolbar, and a dashboard module when anything's waiting.
• Notes appear in the Timeline feed alongside bookmarks and cards, and join the study-notes export.

11The Reader: EPUB

Add the EPUB alongside your audiobook and the Read tab becomes a full book reader, synchronized to the narration.

Importing

Drop the .epub in the book's folder — Echo's auto-import scanner picks it up — or use Import Document in the playlist. Echo parses the book (safely — imports are copy-only and validated), extracts every paragraph, heading, and image, and stores them in its local database. Inline formatting (bold, italics), block quotes, and links are preserved.

Reading

• The book renders as a clean feed of cards: chapter headers, paragraphs, images.
• Follow the narration: the active paragraph is highlighted and the feed auto-scrolls with playback. Scroll away to browse freely; auto-scroll politely disengages and a tap brings you back to the live position.
• Tap to seek: tap any paragraph to jump the audio to that exact text. Tap images to view full-screen.
• Search: full-text search with highlighted matches; tap a result to jump there — in text and in audio.
• Table of contents: the chapter picker navigates the book's structure; the sticky header shows your position as Part → Chapter → Section.
• Highlights: long-press → Change Color to tint passages — build your own color system.
• Typography: font size, line spacing, and card background are adjustable; Lexend and OpenDyslexic (dyslexia-friendly) fonts are built in.
• Reader speed controls 🚧 Coming in 1.0 — adjust playback speed without leaving the Read tab.

The reader toolbar

While the Read tab is active, the bottom toolbar switches to reader-optimized controls: skip back / play–pause / skip forward, timeline, and bookmark — so you can drive playback without leaving the text.

12Audio–Text Alignment

Alignment is what binds the reader to the narration: every paragraph gets a timestamp. Echo builds this map for you and lets you correct it anywhere.

Auto-Align (recommended)

Tap Auto-Align Chapters and Echo's on-device speech recognition (WhisperKit, running on the Neural Engine — no audio ever leaves your device) aligns the book in tiers:

A progress view shows each tier working, with a debug log if you're curious. Between anchors, Echo interpolates positions weighted by paragraph word counts — long paragraphs get proportionally more time. When alignment completes, Echo celebrates your book's % aligned 🚧 Coming in 1.0.

Continuous Alignment (optional, in Settings) keeps refining in the background while you listen: Echo samples short windows of the audio it's already playing, transcribes them on-device, and drops new anchors as it confirms positions.

Manual anchors

Reality is messy — narrators skip forewords and editions disagree. Fix any spot in seconds:

• Long-press a paragraph → Align to Now (or Align to 5s Ago) to lock it to the playhead.
• Heading cards offer Align to Chapter Start/End for bulk anchoring.
• Locked anchors show a green badge with their timestamp; interpolated text shows its estimated status.
• Erase Anchor removes one; Reset Alignment clears the book and starts fresh. Recalculation is instant.

13PDF Companion Documents

Working from a PDF (slides, sheet music, a scanned textbook)? Import it like an EPUB — the Import button accepts both and routes automatically.

• The Read tab renders the PDF with continuous scroll and zoom.
• Page-level alignment: long-press a page → align it to the current audio. The Manual Alignment sheet gives you play/pause, ±5s skips, and a scrubber joystick — pull a little for slow precise scrubbing, more for fast travel, with live audio preview while you drag.
• Page bookmarks: bookmark a page and Echo stores a screenshot thumbnail plus your exact page, zoom, and scroll position — tapping the bookmark restores the view precisely.

14Insights 🚧 Coming in 1.0

Insights is Echo's honest mirror: everything it shows is computed on your device from your own listening and review history. No server ever sees a number. Open it from the dashboard modules or the Timeline toolbar.

What you'll see

The dashboard gets live teaser modules — real listened-today, streak, and upcoming reviews — that tap through to the full screen. On the Mac, a Stats pane shows the Overview, Listening, and Study sections.

15Context Memory (Location) 🚧 Coming in 1.0

Your brain files where alongside what — Echo can capture the "where" for you. Off by default; flip Settings → Privacy & Location → Context Memory to opt in.

What it captures (and what it doesn't)

• Approximate places only: Echo uses reduced-accuracy location — neighborhood level, not your doorstep — and stores a coarse place name like "Maple Ridge, Halifax".
• Three capture points: when a listening session starts, when you create a bookmark, and when a chapter begins. That's what powers bookmark place chips, "Chapter 3 started at Oak Street" in per-book Insights, and the Places list.
• Never blocking: capture is fire-and-forget with a timeout — if location is slow or unavailable (airplane mode, tunnels), your bookmark saves instantly anyway, just without a place.
• Deletable in one tap: Delete Location History erases every captured place — session history, bookmark places, chapter places — immediately and permanently.
• Sync policy: bookmark places travel with bookmarks through your personal iCloud while the feature is on; your session location history never leaves the device. Details in the privacy policy.

16Exports & Your Data

Echo's position on your data: it's yours, in formats you can read, forever. The database schema is open source; nothing is hostage.

17The Playlist & Timeline

Playlist

• Chapters list in playback order with duration and progress; logical chapters expand to show their sections.
• Drag to reorder when filenames sort badly.
• Tap to dim a chapter to skip it ("this is the LibriVox disclaimer track") — dimmed chapters are skipped by playback and loops.
• Hierarchical titles render nested structure (Part 1 → Chapter 1 → Section A) with visual indentation.
• Playlist edits persist per book, and a portable manifest file keeps your ordering if you move the folder between devices.

Timeline

The Timeline tab is your study history as a feed: chapters, bookmarks (with photos and memo indicators), flashcards, notes, and aligned text excerpts, in book order. It's where the dashboard modules live (due cards, streak, listened today, inbox badges) and the fastest place to skim everything you've captured from a book. Freeze the timeline while browsing so it stops following playback, then sync-and-resume when ready.

18Apple Watch

Echo's watch app is a full remote — designed so you never need the phone in your hand (or out of the aux cable).

The remote

• Up to 25 buttons: five pages of five slots, every slot user-assignable: play/pause, skip forward/back (5–60s, configurable), next/previous chapter, next/previous section, loop mode, speed, sleep timer, bookmark, Pomodoro — or empty. Empty pages hide automatically.
• Mark passage 🚧 Coming in 1.0 — one tap drops the moment into your Card Inbox.
• Dictate note 🚧 Coming in 1.0 — speak a Brain Dump note from the wrist; playback never pauses.
• Design it from the phone: drag-and-drop the layout in Settings → Watch App; it syncs to the wrist instantly.
• Digital Crown: assign to volume or scrubbing (with a deadzone so a brushed crown doesn't jump your position).
• Big targets: buttons are sized to hit without looking — gloves, rain, walking.

On-wrist features

• Now playing screen with full-screen artwork (or the classic compact layout) — including photo-bookmark artwork switching, and a tap-for-fullscreen cover viewer.
• Bookmarks with voice memos, recorded on the wrist, delivered reliably to the phone.
• Hands-free flashcard review — full Daily Review sessions on the watch.
• Pomodoro timer — hours/minutes/seconds wheels, a fat progress ring, persistent alarm. Lives right in the button grid.
• Sleep timer start/stop, speed cycling, loop control.
• Complication: current book thumbnail + progress ring on your watch face; tap to open the remote. The optional date overlay puts the day/date on the player screen.

Reliability

State syncs via durable application context — the watch picks up the truth the moment it wakes, even after a weekend off-wrist, and stale commands are never replayed (no phantom pauses or position jumps). If watch and phone disagree, the watch asks the phone for the authoritative position and converges.

19Widgets & Control Center

• Lock Screen / Home Screen widget: current book thumbnail with a progress ring.
• Play/pause from the widget without opening the app.
• Control Center: a toggle-playback control.

20CarPlay

Echo appears in CarPlay with a browse list and remote transport commands — play, pause, skip — through the car's interface. (CarPlay is intentionally minimal for now; richer templates and capture buttons are on the roadmap.)

No CarPlay in your car (Echo's creator doesn't have it either)? That's what the watch remote and aux cable are for. Echo's whole design assumes the phone stays in your pocket.

21Echo for Mac

• Three-pane layout: bookmarks sidebar, player with transport + speed controls, document pane.
• Plays the same folders (broadest format support, including FLAC/OGG/OPUS).
• EPUB alignment with streaming on-device transcription — point it at a book and watch alignment build in real time.
• Transcript pane with live highlighting and search; word-cloud visualization of any book's vocabulary.
• Bookmarks share the same format as iOS and live in the shared app-group store.
• Insights pane 🚧 Coming in 1.0 — listening and study charts on the big screen.
• Review pane 🚧 Coming in 1.0 — clear your due cards at the desk, with menu-bar and keyboard-shortcut basics.

Mac 1.0 is the functional core — play, read, review, see your stats. Full reader/alignment parity with iOS continues after 1.0.

22Sync & iCloud

Echo has no servers and no accounts — sync rides on your iCloud, end to end.

• Today: your audio files sync wherever you keep them (e.g., iCloud Drive), and alignment anchors sync through iCloud so a book aligned once stays aligned.
• Study sync 🚧 Coming in 1.0 — flashcards, decks, bookmarks, and playback position sync across iPhone, Mac, and Watch through your personal iCloud (private database). Edit a card on the Mac, review it on the phone, resume the book on either.
• Sensible conflicts: if two devices disagree, scheduling follows your most recent review and content follows your most recent edit — no duplicate cards, no lost grades beyond the rare double-offline edge case.
• What never syncs: your session location history (see Context Memory) and anything you haven't opted into.
• Voice memos, brain-dump notes, and planned sessions stay device-local in 1.0 — their sync is on the roadmap.

23Settings Reference

24Transcription Tools (Power Users)

The Echo repository ships a companion command-line tool (Tools/transcription_generator.py) for generating full transcripts of your audiobooks on your Mac. EPUB/PDF alignment itself runs entirely inside the app (WhisperKit on-device) and needs none of this — the earlier Swift transcription/alignment CLI has been retired in favour of in-app alignment.

• Python CLI (faster-whisper): transcribe a single file with --audio_path, or a whole folder with --dir (files that already have a .transcript.json are skipped). Tune the run with --model_size, --language, --device, and --force.
• Output is a .transcript.json sidecar of timestamped segments plus word-frequency data (the Mac app renders these as word clouds).

This is optional — the iOS app's built-in alignment needs none of it — but lovely for archival transcripts of your library. Set it up with pip install -r Tools/requirements.txt and brew install ffmpeg.

25Privacy

The shortest section, because there's nothing to disclose:

• No accounts. No analytics. No tracking. No ads. No servers.
• Your books, bookmarks, photos, voice memos, notes, flashcards, and listening history stay on your devices (and your personal iCloud, where you enable sync).
• Speech recognition for alignment runs entirely on-device. Audio never leaves your hardware.
• Location capture (Context Memory 🚧) is opt-in, approximate, and deletable — and session location history never leaves the device. Full details in the privacy policy.
• The app is open source (MIT) — you can read every line: github.com/dfakkeldy/Echo.

26Troubleshooting & FAQ

Library & playback

Reader & alignment

Study & data

Watch, privacy & the project

Echo is open source under the MIT license. Found a bug, or want a feature? Open an issue — the developer reads every one.