PocketSiren privacy policy

Effective date: October 28, 2026

PocketSiren: Anti-Theft Alarm (package app.web.pocketsiren) is an Android app by the developer Trung-Hieu Tran. It is an anti-theft alarm for your own phone: when it is armed and someone moves the phone, takes it out of a pocket or pulls the charger, a loud siren starts and only your PIN stops it. PocketSiren is free to download, with an optional one-time purchase, PocketSiren Pro.

This policy explains what PocketSiren does with your information. The short version: PocketSiren'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. Sensor readings are used on your phone only while it is armed, and your PIN is stored only as a protected hash. Neither ever leaves your phone or reaches the ad networks.

What PocketSiren collects

PocketSiren 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.

Sensor readings, your PIN and the alarm log never leave your phone and are never given to the ad networks.

The free version of PocketSiren shows ads (see the next section), so it has Android's internet, network state and advertising ID permissions. Besides the ad networks' own traffic, PocketSiren 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 PocketSiren's own screens only: a banner on the home screen, the alarm log 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 PIN or alarm screen, while PocketSiren is armed and the siren sounds, during onboarding or over other apps. PocketSiren 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 PocketSiren 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.

Sensors

While PocketSiren is armed, and only then, it reads the phone's motion sensors (accelerometer and significant-motion sensor), the proximity and light sensors (for the pocket and bag alarm) and the charger, earphone, battery and SIM state for the alarms you turned on. These readings are compared in memory with the calibration and sensitivity you chose and are never stored or sent. When you disarm, PocketSiren stops reading the sensors.

To stay armed with the screen off, Android requires a visible notification while PocketSiren is armed (a foreground service).

Your PIN

The PIN that stops the siren is stored only as a salted hash (PBKDF2), never as the PIN itself, in the app's private storage. If you choose to stop the siren with your fingerprint, face or the phone's own screen lock, Android checks it; PocketSiren never sees or stores your fingerprint, face data or screen-lock code.

Full-screen PIN screen

If you allow it (Android's "full-screen intent" access, asked when needed), PocketSiren shows the PIN pad over the lock screen while the siren plays. Without it, the siren keeps going until the PIN is entered in the app or from the notification after the phone is unlocked.

What is stored on your phone

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

• the alarm log: date and time, which alarm was triggered and how it was stopped;
• your settings: the alarms you use, sensitivity and calibration, arming delay, siren sound, presets, schedules, theme and language;
• the PIN hash described above;
• if you choose your own siren sound, a reference to the audio file you picked, so PocketSiren 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.

The log, the settings, the PIN hash and your message for whoever finds the phone are kept in Android's device-protected storage (still private to PocketSiren and on your phone only). This lets "Stay armed after a restart" and the power-on alarm work right after the phone starts, before you unlock it. The PIN hash is still never included in a backup.

Other permissions

• Notifications: the "Armed" notification and alarm notices.
• Do Not Disturb access (optional, asked only if you turn on "Siren even in Do Not Disturb").
• Fingerprint or face (biometric prompt, optional) to stop the siren.
• Vibration, keep awake while armed and run at startup (only for the optional "stay armed after a restart").
• The flashlight is switched with Android's torch function, which needs no camera permission.
• Internet, network state and advertising ID: for the ads in the free version only (see Advertising).
• Not requested: camera, microphone, location, contacts, phone, SMS, call log, storage, device administrator and accessibility.

Purchases (Google Play Billing)

PocketSiren 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). PocketSiren 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 PocketSiren'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 alarm log, the PIN hash, settings and every other record PocketSiren keeps on your phone. Uninstalling the app also removes everything it stored. PocketSiren 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.

Use on your own phone

PocketSiren is made to protect your own phone. It does not track, locate or watch anyone.

Children

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

Changes

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

Contact

Developer: Trung-Hieu Tran.

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