Authentic EngineeringPrivacy Policy
This policy covers the apps published by Authentic Engineering LLC. The first part applies to Zazen Journal, Three Numbers and Tuneshed; after it, each app has its own section listing exactly what it records. Practice Companion works differently, in your browser and with your own Dropbox, and its section says everything it keeps and sends.
What Zazen Journal, Three Numbers and Tuneshed don't do
- No accounts, sign-in, or user profiles.
- No analytics, crash reporting, or tracking SDKs.
- No advertising.
- No third-party services receive your data.
- No connection to any server operated by us. The apps make no network requests of their own.
The apps do not collect your name, email, location, contacts, or any identifier for you or your device.
If a future version of any of our apps adds anything to what it records or sends — for example anonymous usage statistics — this policy will be updated first, and the change will be described in the App Store release notes.
Where data is kept
Each app saves what it records inside its own storage on your iPhone and on your Apple Watch. The two copies are kept in step using Apple's WatchConnectivity, which runs directly between your paired iPhone and Apple Watch. The data never passes through a server operated by us or anyone else.
Tuneshed has no Apple Watch app: it keeps what it saves on the iPhone or iPad you use it on, and nowhere else.
Your devices' normal iCloud or iTunes backups may include the apps' storage, subject to your own backup settings. We have no access to those backups.
Zazen Journal
What the app records
For each session, Zazen Journal stores:
| Data | Where it comes from |
|---|---|
| Start time and duration | The timer you start and stop on the watch |
| Average and maximum heart rate | Apple Health (HealthKit), read live during the session — only if you grant permission |
| Weight (optional) | Entered by you after a session, on either device |
| Watch thermal state changes during the session | The Apple Watch's own device-pressure level (normal, fair, serious, critical) and when it changed — used to tune the thermal warning. This is not a temperature and not a body measurement. |
That is the complete list. When you finish a session or edit a weight, the app sends the updated list to your other device as described above.
Apple Health
Zazen Journal asks for permission to read heart rate so it can show and record it during a session. To keep the timer running in the background and read heart rate live, it runs an Apple Watch workout session while you meditate, which is why it also asks for permission to share workouts. The app does not save any workout or other data to the Health app.
Health data is used only to display heart rate during a session and to store the session's average and maximum. It is never transmitted off your devices except to your own paired device as described above, and it is never used for advertising, analytics, or shared with any third party. You can revoke access at any time in the Health app under Sharing → Apps and Services → Zazen Journal.
Deleting your data
Deleting Zazen Journal from a device removes all session data stored on that device. Because your iPhone and Apple Watch each keep their own copy, delete the app from both to remove everything. The current version does not yet offer deletion of individual sessions inside the app.
Three Numbers
What the app records
For each game, Three Numbers stores:
| Data | Where it comes from |
|---|---|
| Team or player names | Typed by you when you start a game; “Blue” and “Orange” if you leave them alone |
| The game's rules | Your choices when you start a game: doubles or singles, the score to play to, the winning margin, and who serves first |
| The rally-by-rally log and the score | Each rally you score by voice or by tap, and each correction you make |
| When the game started, was last changed, and ended | The device's clock |
That is the complete list. While a game is being played, the app sends it to your other device as described above, so the phone and watch show and call the same score.
Microphone and speech recognition
Three Numbers uses the microphone only while the Listen switch is on, or while you hold the microphone button on the watch. Listening continues with the screen locked or the app in the background until you turn Listen off.
What the microphone hears is turned into text by Apple's speech recognition running on your iPhone. The app requires on-device recognition: if your device can't do that, voice commands are unavailable rather than being sent to a server. The audio is not recorded or kept, and the recognized words are used only to find a command such as “point Blue” or “undo”. They are not saved with the game or written to any log.
Apple Watch cannot recognize speech on its own. When you hold the microphone button on the watch, the app records for as long as you hold it (at most 8 seconds) and sends that clip directly to your paired iPhone, which recognizes it on-device in the same way. The clip is deleted from the watch as soon as you let go and from the iPhone as soon as it has been recognized.
If the iPhone is out of reach, pressing the watch's microphone button opens watchOS's standard text input screen instead. If you choose dictation there, that is Apple's dictation feature and is handled under Apple's privacy policy and your own Siri & Dictation settings, not by Three Numbers.
To help the recognizer hear your team names, the app builds a small vocabulary file from the names in the current game and keeps it in its cache on your iPhone. It never leaves the device.
Deleting your data
On iPhone, swipe a game in History to delete it. Deleting Three Numbers from a device removes everything it stored on that device. Because your iPhone and Apple Watch each keep their own copy, delete the app from both to remove everything. You can withdraw microphone or speech recognition permission at any time in Settings → Privacy & Security; tap scoring keeps working without them.
Practice Companion
Practice Companion is a web app at gcaglar.github.io/music, with an optional app you install on your own computer to work songs out. There is no account with us, no analytics or tracking, no advertising, and no server of ours: the site is static files, and everything the app does happens in your browser, on your own computer, or in your own Dropbox.
What it keeps, and where
| Where | What |
|---|---|
| Your browser, on that device | Sessions you open from a zip file, your settings, and your corrections to those sessions, in the browser's own storage for the site. Remove a session with the ✕ next to it, or clear the site's data in your browser. |
| Your Dropbox, if you connect it | Only the app's own folder, Apps › Practice Companion: the app reads your sessions there and saves your chord and lyric corrections, chord shapes and the songs you add. The sign-in token is kept in your browser. Disconnect with Sign out, or remove the app in Dropbox's settings under Connected apps. |
| Your computer, with the app installed | Your songs, what the app works out from them, and your corrections, in a sessions folder on your computer that you choose. The analysis runs on your computer. |
What it sends, and to whom
| To | What, and when |
|---|---|
| Dropbox | When you connect it: the app's requests to your own Dropbox, to list, open and save sessions in its folder, to make links when you share a session, and to copy a session someone shared with you into your folder. Handled under Dropbox's own privacy policy. |
| Anyone you give a link | Sharing a session makes Dropbox links to its files. Anyone with the link can open that session, read only, until you stop sharing it. |
| LRCLIB (lrclib.net) | With the app installed: a session's name, to look up the song's published lyrics. Only the name is sent. Turn it off in Settings. |
| GitHub | The site and the installer are served by GitHub Pages, which, like any web host, receives your IP address and browser details with each request. The installed app asks there whether a newer version is out. |
| Hugging Face, PyTorch and GitHub | With the app installed: the models it uses to hear the music are downloaded from their publishers the first time each is needed. Nothing of yours is sent. |
| A link you paste | Opening a zip file from a link fetches that link. |
Microphone and the sound of a tab
The microphone, or an input of your audio interface, is used only while you sing along or the tuner is open. The pitch is worked out in your browser. What you sing is kept in the page's memory so that you can hear it back, and is gone when you leave the song or close the page. When you use the installed app, your pitch and what you sing are also sent to it on your own computer, which keeps them in memory only; they don't leave the computer.
When you listen to a tab, Chrome shares that tab's sound with the page, which sends it to the app on your own computer to be worked out and kept there as a session.
Reporting a problem
Report a problem opens a new issue page at GitHub with the song's name and the moment you were at filled in. Nothing is sent unless you submit it there.
Deleting your data
Remove sessions kept in your browser with the ✕ next to them, or by clearing the site's data. Sessions in Dropbox or on your computer are ordinary folders: delete them there. Stop sharing a session from its Share… panel, which takes its links back.
Tuneshed
What the app records
Tuneshed stores:
| Data | Where it comes from |
|---|---|
| Your settings | Your choices in the app: instrument, tuning, capo, reference pitch, how the tuner reads and shows notes, and the metronome's tempo, meter, beats, sound, flash and haptics |
| Custom tunings | The names and notes of tunings you make |
That is the complete list. It stays on the device you use Tuneshed on.
Microphone
Tuneshed uses the microphone only while its tuner is on screen and the app is in front. It stops listening when you switch to the metronome, leave the app, or lock the screen. What the microphone hears is analyzed on your device, as it arrives, to find the pitch of the note you're playing. It is not recorded, saved, or sent anywhere. The metronome never uses the microphone.
Deleting your data
Delete a custom tuning from the tuning menu: choose it, then Edit and Delete Tuning. Deleting Tuneshed removes everything it stored. You can withdraw microphone permission at any time in Settings → Privacy & Security → Microphone; the metronome keeps working without it.
For all our apps
Children
Our apps are not directed at children under 13 and do not knowingly collect information from them.
Changes
If this policy changes, the new version will be posted at this address with an updated effective date.
Contact
Questions about privacy: support@authenticeng.com.