Last updated: September 30, 2026
This is a translation of the original Spanish policy, which prevails in case of any discrepancy.
Sound Tools is a tuner, metronome and sound analyzer. This same policy applies to both versions of the app:
Both do the same thing and handle your data the same way. Where there are differences —because the stores and operating systems work differently— we state explicitly which is which. This page explains, plainly, what the app does with your data.
The tuner and the analyzer need the microphone to listen to your instrument. That sound is processed in real time and on your device: it is not recorded, not saved to any file and not sent to any server. Not ours, not anyone's. When you close the screen, the audio ceases to exist.
This is literal: the microphone samples travel in memory from the capture engine to the analysis engine, which returns a note, a deviation in cents or a spectrum, and are then discarded. The app has no recording feature, no way to export audio and no way to share it.
The app has no sign-up or sign-in, so we do not collect your email address, your name or any identifier of yours. Nor is there any Sound Tools server that the app calls: the catalog of instruments and tunings ships inside the app itself.
What you enter in your profile —name, bio, city, country and instruments, with their
level, years of experience and preferred tuning— is stored only in your device's
local storage and is never transmitted to us. On Android this is the app's
private SharedPreferences; on iOS, its equivalent. You type the city and
country in yourself: the app never queries the device's location and,
on Android, does not even declare a permission to do so.
If you delete the app, that data disappears from the device.
An honest caveat about Android: the app allows system backup. If you have Android backup turned on, the system itself may include the app's local settings (profile, instruments, setlists, calibration) in the backup of your Google account, and restore them when you switch phones. That backup is yours and is managed by Android; we cannot see it and have no access to it. You can turn it off in Settings → Google → Backup.
The free version shows ads from Google AdMob. The paid version (“Sound Tools Pro”) shows none.
To serve those ads, Google may collect and process data from your device, including the advertising identifier and usage data. Google acts as the controller for that processing; how it works is described in Google's privacy policy.
There are never ads while you are measuring. The tuner, the analyzer and the metronome screen are kept clean on purpose, because there visual precision is the product.
| Format | Where |
|---|---|
| Banner | Fixed at the bottom of the Profile screen and of the setlist list. |
| Full screen (interstitial) | When closing the setlist list and when finishing a long metronome session, never during measurement. |
| Full screen (app open) | When returning to the app from another app, only if the ad was already loaded. Never on a cold start, and never when returning from a system dialog, from the purchase flow or from another ad. |
In the European Economic Area and the United Kingdom, the app shows Google's consent form (UMP, “User Messaging Platform”) before requesting any ad. If there is not sufficient consent, the app does not request ads and the advertising SDK is not even initialized.
You can reopen that form at any time from Profile → Privacy and terms → Ad privacy options. That button appears precisely where Google requires it to be offered.
Android has no tracking dialog like Apple's, so the app does not ask you for one. You
control the Android advertising ID yourself from Settings → Google →
All services → Ads, where you can delete it or turn off personalization without the
app being able to prevent it. The app declares the
com.google.android.gms.permission.AD_ID permission because the ads SDK needs
it on Android 13 and later; the app's code does not read that identifier,
it is used only by Google's SDK. The ads SDK also declares, on its own, Android's
Privacy Sandbox permissions (ACCESS_ADSERVICES_AD_ID,
ACCESS_ADSERVICES_ATTRIBUTION and ACCESS_ADSERVICES_TOPICS),
which are the mechanism the system itself uses to manage advertising.
On iOS the app will ask your permission to track your activity (Apple's “App Tracking Transparency” dialog). You can say no: ads will still be shown, but not personalized. In the European Economic Area and the United Kingdom you will also see Google's consent form, and you can reopen it at any time from Profile → Ad privacy options.
The Apple Watch app shows no ads and sends nothing over the network.
“Sound Tools Pro” is a one-time purchase that removes ads. It is not a subscription and does not renew.
Payment is handled entirely by the store —Apple on iOS, Google Play on Android—: we do not see or store your card details. All we receive from the store is confirmation of whether or not your account has the purchase, so we know whether to hide the ads.
On Android that confirmation is requested from Google Play each time it is needed, and no local copy is kept of the receipt or of the purchase identifier. That is why there is a “Restore purchase” button in Profile: it asks Google Play again, using the account you are signed in to the store with.
| Permission | What for |
|---|---|
Microphone (RECORD_AUDIO) | Listening to your instrument in the tuner and the analyzer. It is processed on the device and not recorded. |
| Internet and network state | Only for Google services: ads, the consent form and billing. The app does not call any server of its own. |
Advertising ID (AD_ID) | Required by Google's ads SDK. The app does not read it. |
| Vibration | The metronome's haptic pulse. |
Billing (com.android.vending.BILLING) | Purchasing Sound Tools Pro through Google Play. |
The app does not request location, camera, contacts, storage or access to your photos, and it does not ask for your age or date of birth.
| Data | Who processes it | What for |
|---|---|---|
| Microphone audio | Only your device | Tuning and analysis in real time. It is not recorded or sent. |
| Profile and instruments | Only your device (and, if you have it turned on, your system backup) | Remembering your preferences between launches. |
| Advertising ID and usage data | Google AdMob | Showing and measuring ads. Only if you consent. |
| Purchase status | Apple (iOS) or Google Play (Android) | Knowing whether ads should be hidden. |
We do not use any analytics or measurement tools of our own: there is no Firebase Analytics, no Crashlytics and no equivalent SDK in the app.
The app is not directed at children under 13 and does not knowingly collect data from them. On the App Store it is rated 4+.
Since we do not store any of your data on any server, there is nothing we can export or delete on request: everything the app knows about you is on your device and under your control. In practice:
If what the app does with data changes, this page is updated and the date at the top changes.
For any questions about privacy: gbrayhan@gmail.com