UcanTune Privacy Policy

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Effective date: September 21, 2026

UcanTune does not collect personal information. There is no account and no server, and everything the app creates stays on your device.

This policy covers all three UcanTune releases — the phone and tablet app (com.onlyone.ucantune), the Wear OS build of the same app, and the separate watch face UcanTune Face (com.onlyone.ucantune.watchface). None of them collect personal information.

The same text is shown in the app under Settings → Privacy policy. That copy is updated through app releases, so for a few days after a change this page may be ahead of it — when they differ, this page governs.

1. Personal information we collect

None.

This app does not collect or ask for any personal information, including your email address, phone number, date of birth, location, contacts, device identifiers, or advertising identifiers. There is no sign-up step, and the app does not create any value used to tell one user from another.

One thing deserves its own note — the member label in Lesson mode. When several people share one device, you can tag practice records with a label so they stay apart (Pro). It is a label you type in yourself, it is attached only to practice records on the device, and it never leaves the device. The app neither asks for it nor checks it — "my brother" or "Tuesday 3pm" works just as well. If you do not use the feature, no label is created. Section 9 explains how to remove one.

2. Data transmission

This app does not declare the internet access permission (INTERNET). Android blocks network access at the operating system level for an app without that permission. The developer has no server and cannot receive any of your data.

There are exactly two paths off your device, and both go only to a device you paired yourself.

• Wear OS watch sync — when the UcanTune Wear app is installed on a watch paired to the same Google account, only the values below travel over the Android Wear data layer (Google Play services). None of them identify a person.
• Phone to watch — metronome BPM, time signature, tuning preset, A4 reference frequency, transpose, Pro status
• Watch to phone — metronome BPM, tuning preset, A4 reference frequency, transpose, and a single number for today’s total practice time

Audio and recordings are never sent in either direction. The only practice figure that leaves the watch is today’s total; individual records such as start and end times stay on the watch. If you do not use a watch, this sync never happens.

• Bluetooth page turning — on the Visuals screen the app sends arrow-key presses only to a device you already paired and selected (an iPad, for example). Your phone acts as a Bluetooth keyboard; no app data is sent.

Neither path passes through the developer.

3. Microphone

The microphone is used in the places below. Only two of them write a file, and both only while you have started a take.

• Tuner — to work out the pitch of your instrument. Incoming sound is used in memory to compute a frequency in real time and is discarded immediately. Nothing is written to a file.
• Record — sound is written to a file only while a recording is running. Nothing is saved unless you press the record button. Where those files live and how to delete them is in sections 4 and 9.
• Visuals — used only to draw the loudness curve and name the chord you are playing, both on the full screen and in the preview you pick it from. Like the tuner, it discards the sound as it arrives and writes no file.
• Rhythm and Solo practice — when you play along on your instrument instead of tapping the screen, to work out *when* and *what* you played. Discarded as it arrives; no file is written.
• On your own — to play your take back over the backing, twelve bars are held in memory. They are discarded once played back. No file is written; use the Record feature if you want to keep a take.
• Layered takes (Looper) — while you have started a take, your playing is saved to a file. It lives in an app-private folder no other app can read; section 9 explains how to remove it.
• Latency calibration — used only while measuring how long sound takes to travel from the speaker back to the microphone. It lasts a few seconds and writes no file.

In none of these cases does sound leave the device — this app has no internet permission, and neither the watch sync nor the page turner carries audio (see section 2). A recording leaves the app only when you press Share or Export. Share hands the file to the Android share sheet and the app takes no part in where it goes; Export copies it into the one folder you pick at that moment — the app asks for no storage permission and can neither read nor write anywhere you have not pointed it.

If you decline the microphone permission, the metronome and the rhythm practice features still work. You can revoke the permission at any time in your device settings.

4. Data stored on your device

The following data is stored only on your device.

• Practice records: when you practiced and for how long, the mode, the tempo (BPM), scores and judgement counts, and timing error statistics — in the database file ucantune.db
• App settings: theme, language, A4 reference pitch, and tap latency offset — in DataStore files
• Recordings: audio you recorded — m4a files in the app-private recordings folder
• Looper projects: the layers you recorded and their settings — audio files in an app-private folder
• Member labels: the labels you typed in Lesson mode — inside the practice records file above

Android gives every app its own private storage area, so these files cannot be read by other apps. They contain nothing that identifies a person.

If you uninstall the app or reset the device, the recordings go with it. They are not in cloud backup either (see 5). To keep them, select takes on the Record screen and use Export to save a copy into a folder of your choice — those copies live on independently of the app.

5. Android automatic backup

If you have turned on Android automatic backup, the practice records and settings above may be included in the backup of your own Google account.

Recordings are excluded from cloud backup. The automatic backup quota is 25MB per app and a single recording in this app can run for up to an hour, so one long take would push the practice records you actually want kept out of the backup along with it. If you want to keep a recording, use Export on the Record screen to save it into a folder of your choice, or send it elsewhere with the share button. A direct device-to-device transfer does carry recordings across.

That is a feature of the Android operating system, not data sent by this app. Backed-up data is handled under Google policies and the developer cannot access it.

The tap latency offset (calibration) is explicitly excluded from backup. That value only means something on the device where it was measured, so carrying it to another device would throw off timing judgement instead of helping.

You can turn automatic backup off in your device Android settings.

6. Permissions declared by the app

These are all the permissions the phone app declares.

The app does not declare internet, location, contacts, photo, external storage, or camera permissions.

The metronome's flash cue toggles the torch (CameraManager.setTorchMode) rather than taking a picture, so no camera permission is needed.

Apps downloaded from the Play Store carry one more, com.android.vending.CHECK_LICENSE. This app does not declare it — Google Play adds it when it builds the distribution file, and Play uses it to check whether you own a purchase. We can neither add nor remove it, and it grants access to no data.

The watch app — UcanTune Wear

These are all the permissions the watch app declares.

The watch app has no internet permission either. What travels between watch and phone is listed in full in section 2.

The watch face — UcanTune Face

It declares no permissions at all. It is a declarative watch face (Watch Face Format) with no executable code, so it has no means of sending anything on its own.

The values on the dial are handed to it by the watch's watch-face runtime. Tempo, tuning and practice time come from the UcanTune Wear app on the watch; step count, step goal, temperature and weather condition come from what the watch already holds (from the Info face, September 2026). The watch face does not store those values, does not send them anywhere, and uses them only to draw the dial. It holds no health or location permission — the runtime reads them and passes across the values alone.

7. Third parties, advertising, and analytics

This app contains no advertising SDK and no usage analytics SDK.

We do not share or sell user data to third parties. There is no collected data to share in the first place.

8. Children

This app is not directed to children under 13.

Because the app collects no personal information from anyone, including children, there is no data for a parent or guardian to request the deletion of.

9. Deleting your data

Uninstalling the app removes the practice records, settings, and recordings stored on your device along with it.

Recordings can also be deleted one by one from the list on the Record screen. A deleted take goes to the trash, and emptying the trash removes it from the device.

Looper projects can be deleted from the list on the Looper screen; deleting one also removes the audio files inside it. Member labels in Lesson mode can be renamed or deleted from the Lesson screen.

The developer holds no data, so there is nothing to send a deletion request for. Data included in Android automatic backup can be removed from your own Google account settings.

10. Changes to this policy

If this policy changes, the text on the in-app screen is updated with an app update and the effective date above is revised.

If a change affects what information is collected, we will also announce it inside the app.

11. Contact

If you have any question about this policy or about how your data is handled, please get in touch.

ucanguitar@gmail.com

UcanTune · com.onlyone.ucantune · com.onlyone.ucantune.watchface