EchoFind privacy policy

Effective date: October 28, 2026

EchoFind: Clap to Find Phone (package app.web.echofind) is an Android app by the developer Trung-Hieu Tran. When you clap or whistle, your phone rings, vibrates and flashes so you can find it. EchoFind is free to download, with an optional one-time purchase, EchoFind Pro.

This policy explains what EchoFind does with your information. The short version: EchoFind's own code collects and shares nothing about you. The free version shows ads from Google AdMob and Unity Ads, whose SDKs collect some device data, described below; buying Pro removes every ad. The sound it listens to is analysed on your phone and thrown away at once. It is never recorded, saved or sent anywhere, and never given to the ad networks.

What EchoFind collects

EchoFind itself collects nothing about you. It has:

• no account and no sign-in;
• no analytics, no crash reporting and no tracking of our own;
• no server of ours.

The sound from the microphone, your find history and your settings never leave your phone and are never given to the ad networks.

The free version of EchoFind shows ads (see the next section), so it has Android's internet, network state and advertising ID permissions. Besides the ad networks' own traffic, EchoFind makes one request of its own: it asks FightTech's server (fighttech.vn) which ad networks and formats are switched on for this app. That request carries only the app's package name (and, like any internet request, your IP address); it is not used to identify you.

Advertising (Google AdMob and Unity Ads)

The free version shows ads from Google AdMob (Google Mobile Ads SDK) and Unity Ads, in EchoFind's own screens only: a banner on the home screen, the history and Settings, now and then a full-screen ad at a natural pause, and a video ad only if you choose to watch one to try Pro features for 24 hours. Ads never appear on the "Found me! Tap to stop" screen, while the phone is ringing to be found, in the 10 minutes after you found it, on the microphone notice, during onboarding or over other apps. EchoFind asks for your consent with Google's User Messaging Platform where the law requires it (for example in the European Economic Area, the UK, Switzerland and some US states) before any ad is requested; you can change your choice at any time in Settings › Ad privacy choices. To show, limit and measure ads and to prevent fraud, these SDKs may collect and process:

• the device's advertising ID (Android "AD_ID" permission), the app set ID and other device identifiers;
• device and app information, such as device model, operating system, language, app version and your interactions with ads (Unity may also record purchases made through its ads and app usage times);
• approximate location derived from the IP address;
• diagnostics, such as SDK performance data.

This data is collected by Google and Unity, not by the developer, and is sent encrypted. Depending on your consent and region, ads may be personalized or non-personalized. You can reset or delete your advertising ID, or opt out of personalized ads, in Android's settings. Buying EchoFind Pro removes every ad (Settings › Remove ads). On Android 4.3 to 5.1, where Pro cannot be bought through Google Play, the app shows no ads. See https://policies.google.com/technologies/partner-sites, https://policies.google.com/privacy and https://unity.com/legal/privacy-policy.

Microphone

EchoFind uses the microphone (Android's "Microphone" permission, asked only after EchoFind explains why) to hear a clap or a whistle, only while you have listening turned on.

• The sound is analysed in memory, in short frames of a few hundredths of a second, to decide whether it was a clap or a whistle, and each frame is discarded at once.
• While listening, audio is never recorded, never saved to a file and never sent anywhere. The one exception is your own

choice: if you record "your own reply" (Pro), those 3 seconds are saved in EchoFind's private storage on the phone, as described below.

• To keep listening with the app closed and the screen off, Android requires a visible notification while EchoFind listens (a foreground service of type "microphone"). The notification has Pause and Stop buttons. On Android 12 and newer, Android also shows its green microphone indicator the whole time listening is on.
• You can stop listening at any time from the app, the notification, the widget or the Quick Settings tile.

What is stored on your phone

EchoFind keeps these only in its private storage on your device:

• the history of finds: date and time, whether it was a clap, a whistle or a test, a detection score and level, and how the alert was stopped (no sound is kept), plus the self-check after Start and the low-battery chirp;
• your settings: sensitivity, sounds, ring length, vibration and flash choices, schedules, theme and language;
• for the rings you mark "That wasn't me", a numeric sound signature (19 numbers describing the sound's spectrum, so the same

noise can be ignored next time) and, once an hour while listening, the room's noise level as one number. No sound is ever recorded or kept, and none of these numbers leaves your phone;

• if you teach it a sound of your own (Pro), a numeric description of that sound: for each of your three samples, 13 numbers

per 10 ms (the shape of its spectrum over time), so EchoFind can recognise the same kind of sound later. The samples are turned into numbers as they are heard; no recording is kept, and the numbers never leave your phone. "Forget my sound" or Delete everything removes them;

• if you teach it a spoken phrase (Pro, beta), a numeric description of your phrase, made the same way as a taught sound

(13 numbers per 10 ms for each of three takes). There is no speech-to-text and no internet: EchoFind never knows the words, only how the sound is shaped. No recording is kept, the numbers never leave your phone, and "Forget my phrase" or Delete everything removes them;

• if you make one (Pro), your own reply: the 3-second recording you made on the "Your own reply" screen, or the phrase

you typed, spoken by the phone's own offline voice, saved as a short audio file in EchoFind's private storage. It is played only when the phone rings and never leaves your phone. "Remove my reply" or Delete everything deletes it;

• if you write one, your message for whoever finds the phone (for example a phone number to call), shown on the stop screen while the phone rings, also over the lock screen. It is never sent anywhere;
• if you choose your own ring sound, a reference to the audio file you picked with Android's file picker, so EchoFind can play it (the file is not copied or sent);
• if you buy Pro, the Google Play purchase receipt, cached so Pro keeps working offline.

Other permissions

• Notifications: the "Listening" notification with Pause and Stop, and a "Tap to keep listening" notice after a restart or an app update.
• Full-screen alert (optional, asked when needed): shows the "Found me! Tap to stop" screen over the lock screen while the phone rings. Without it you get a normal notification with Stop.
• Do Not Disturb access (optional, asked only if you turn on "Ring even in Do Not Disturb").
• Vibration, keep awake while listening and run at startup (to show "Tap to keep listening" again after a restart).
• The flashlight is switched with Android's torch function, which needs no camera permission. EchoFind does not use the camera.
• Internet, network state and advertising ID: for the ads in the free version only (see Advertising).
• Not requested: camera, location, contacts, phone, SMS, call log, storage and accessibility.

Purchases (Google Play Billing)

EchoFind Pro is a one-time purchase handled by Google Play. The payment takes place in the Google Play Store app, and Google's privacy policy applies to the payment (https://policies.google.com/privacy). EchoFind never sees your payment details. It receives only the signed purchase from the Play Store app on your phone, checks it on the device and does not send it anywhere. There is no account: Pro is restored from Google Play with the same Google account. The Google Play Billing library contains Google components that may send library diagnostics (no payment details) to Google.

Backups and exports

• CSV export and backup files are made only when you ask, and are saved or shared only where you choose.
• Android backup: if your phone's own backup is on, Android may copy EchoFind's settings to your Google account under Google's policy. The purchase receipt is always left out; Pro is restored from Google Play.

Deleting your data

Settings › Privacy and data › Delete everything removes the history, settings and every other record EchoFind keeps on your phone. Uninstalling the app also removes everything it stored. EchoFind keeps no copy on any server. Data held by the ad networks: reset or delete your advertising ID in Android's settings, and see Google's and Unity's privacy policies for their access and deletion requests.

Children

EchoFind is not directed at children and is intended for users aged 13 and older. EchoFind does not knowingly collect data from children.

Changes

If this policy changes, the new version is published at https://echofind-app.web.app/privacy/ with a new effective date.

Contact

Developer: Trung-Hieu Tran.

Contact: through the Google Play listing's developer contact.