Privacy Policy for DeviceMint

App: DeviceMint: Phone Diagnostics Package name: com.mobilecastle.devicemint Publisher: Mobile Castle Effective date: 29 October 2026

This policy is for the free version of DeviceMint, which offers no in-app purchases.

This Privacy Policy explains what information the DeviceMint app (“DeviceMint”, “the app”, “we”, “us”) does and does not handle, and how. Please read it together with the policies of the third parties named below.

By using DeviceMint you agree to the practices described here.

Summary (plain language)

• DeviceMint has no user accounts and no sign-up. We do not ask for your name, email, phone number, or any similar personal detail.
• Your test results stay on your device. The hardware tests run on your phone or tablet, and their results, history and reports are stored only there; a report leaves your device only when you share it. Mobile Castle does not operate any server that receives them.
• Camera pictures and microphone recordings are never saved. They are kept in memory only while you check them, then discarded.
• DeviceMint never reads your IMEI, serial number, phone number or accounts.
• DeviceMint shows ads through Google AdMob, a third party. To serve ads, AdMob may collect device information and an advertising identifier. Ads never receive your test results, measurements, reports, photos or recordings.
• No purchases in this version. DeviceMint offers nothing to buy: it does not connect to Google Play Billing, and it does not ask for the billing permission. Premium features are coming soon.

The rest of this policy gives the detail behind that summary.

Information DeviceMint itself collects

DeviceMint does not collect personal data on its own servers, because Mobile Castle does not run a server that receives your data. Specifically:

• No account / identity data. There is no login, so we do not collect a name, email address, password, phone number, or profile.
• No upload of test data. Results, measurements, reports, camera pictures and recordings are not copied to us.
• No analytics SDK operated by us. DeviceMint does not embed our own analytics, crash-reporting or tracking service. (Google AdMob and the other Google services described below are independent third parties with their own data handling.)

Data that stays on your device

Some information is stored locally on your device so the app can work and remember your settings. This data is not transmitted to Mobile Castle, and it is excluded from Android’s cloud backup. It includes:

• Test results and history: for each run, the tests, their results (for example Passed or Not supported), the measurements shown with them (such as battery level and voltage, GPS time to fix and accuracy, the number of Bluetooth devices or Wi-Fi networks found), the device model and Android version, and the date. They are saved in a database in the app’s own private storage. This version shows the latest five results; older ones stay on your device, locked, and are never deleted on their own.
• Your preferences: for example theme and language.
• Reports you create: a PDF report is written to the app’s private cache only so you can share it; reports older than a day are deleted the next time a report is made. A text report goes straight to Android’s share sheet.
• A local diagnostic log: DeviceMint writes a technical log (which tests ran and their outcome, errors) to a file in the app’s own folder on your device, to help troubleshoot problems on real hardware. It contains no photos, recordings, position, or names of the networks and devices a scan finds, and it stays on your device unless you deliberately share it.

All of it is removed when you uninstall DeviceMint. Settings → Clear history removes your results, and Clear all local data removes results and settings. See Data retention and deletion below.

Hardware tests and what they touch

Each test reads only what it needs from your device, on your device. Every permission is requested only when you start the test that needs it, and the rest of the app keeps working if you say no.

• Cameras show a live picture and take one photo so you can check it. The photo is held in memory only and is never saved or sent anywhere.
• Microphone records a few seconds and plays them back to you. The recording is held in memory only and is never saved or sent anywhere.
• GPS checks that your device can get a location fix. DeviceMint records only the time it took, the accuracy and the number of satellites, never your position.
• Wi-Fi and Bluetooth check the connection and count nearby networks or devices. Their names and addresses are not stored.
• NFC and USB record only the type of tag, or the type and vendor/product number of a connected USB device. The contents of a tag are not read.
• Fingerprint and face unlock use Android’s own biometric prompt. DeviceMint only learns whether you were recognised and never receives fingerprint or face data.
• Device information (model, Android version, memory, storage, screen, processor, sensors, battery) is read from Android to show you and to put in your reports. Android does not give apps the IMEI or serial number, and DeviceMint does not try to read them.

Advertising (Google AdMob)

DeviceMint is free and supported by ads served through Google AdMob, a Google service. Ads appear as banners on the Home, Tests, History and Settings screens and on finished results, never during a test, a camera preview, a recording, the touch test, a location fix or Android’s permission prompt. There are no full-screen ads when you open the app or move between screens.

The ad requests DeviceMint sends carry no content from the app: no test result, measurement, report, photo or recording is ever passed to AdMob. To select and show ads, Google AdMob (and the Google Mobile Ads SDK included in the app) may collect and process information such as:

• a device advertising identifier (Android Advertising ID),
• device and network information (for example device type, operating-system version, approximate location inferred from your IP address, and similar technical data),
• ad-interaction and app-usage data related to the ads shown,
• crash and diagnostic information about the ads software itself.

Google uses this information to serve and measure ads and to help prevent fraud and abuse, in accordance with Google’s own policies. Where required by law (for example, for users in the European Economic Area, the UK and Switzerland), DeviceMint uses Google’s User Messaging Platform to show a consent form before serving personalised ads, and no ad is requested until that choice is made; you can change your choice at any time in Settings → Privacy options. You may also choose to watch a short rewarded ad to unlock one PDF report; this is optional, and the app says what the ad unlocks before it plays.

• Google Privacy Policy: https://policies.google.com/privacy
• How Google uses information from sites or apps that use its services: https://policies.google.com/technologies/partner-sites
• AdMob / Google Ads policies: https://support.google.com/admob/answer/6128543

You can limit ad personalisation and reset your advertising ID in your device settings (Settings → Google → Ads on most Android phones).

Purchases

This version of DeviceMint offers no in-app purchases. It does not connect to Google Play Billing, and no part of the app can start a payment. It asks for no billing permission. Features planned for a future Premium version show “Premium features are coming soon.” If purchases are added in a later version, this policy will be updated before that version is released.

App permissions and why they are needed

DeviceMint requests the following Android permissions. Each is used only for the feature described:

• Camera (CAMERA): for the camera tests.
• Microphone (RECORD_AUDIO): for the microphone test.
• Location (ACCESS_FINE_LOCATION, ACCESS_COARSE_LOCATION): for the GPS test, and on Android 11 and below for the Bluetooth scan. If you have already allowed it, the Wi-Fi test also uses it to count nearby networks. Only while the app is open; there is no background location.
• Nearby devices (BLUETOOTH_SCAN, and BLUETOOTH / BLUETOOTH_ADMIN on Android 11 and below): for the Bluetooth test. Declared as not used to derive your location.
• NFC (NFC): for the NFC test.
• Vibrate (VIBRATE): for the vibration test.
• Biometrics (USE_BIOMETRIC, and USE_FINGERPRINT, which the AndroidX Biometric library adds for older Android versions): for the fingerprint / face unlock test.
• Audio settings (MODIFY_AUDIO_SETTINGS): to play the earpiece test’s tones through the earpiece.
• Network and Wi-Fi state (ACCESS_NETWORK_STATE, ACCESS_WIFI_STATE, CHANGE_WIFI_STATE): for the Wi-Fi test, and to check whether you are online.
• Internet (INTERNET): to load ads. Test data is not sent.
• Added by the Google libraries: the advertising ID and Android’s privacy-preserving ad APIs (AD_ID, ACCESS_ADSERVICES_AD_ID, ACCESS_ADSERVICES_ATTRIBUTION, ACCESS_ADSERVICES_TOPICS) for ads; and background-work permissions (WAKE_LOCK, RECEIVE_BOOT_COMPLETED, FOREGROUND_SERVICE) that the Google libraries use for their own short tasks.

DeviceMint asks for no contacts, accounts, phone, SMS, call log, storage or background-location permission.

Third-party services

DeviceMint relies on the following third parties. Their handling of information is governed by their own privacy policies:

When you share a report, Android’s share sheet sends it to the app you choose (for example email or a messenger). What that app does with it is governed by its own privacy policy.

Children

DeviceMint is a general-audience utility and is not directed at children. We do not knowingly collect personal information from children. The app is intended for general audiences and, in line with the store listing, is not aimed at or designed to appeal to children.

Because the app shows ads, it follows Google Play’s Families and ads policies for a general-audience app. If you believe a child has used the app in a way that raises a concern, please contact us using the details below.

Data retention and deletion

Data stored locally by DeviceMint (test results and history, preferences, reports and the diagnostic log) stays on your device and is retained until you remove it. DeviceMint never deletes your results on its own: this version shows the latest five results and keeps the rest on your device, locked, not deleted.

You can delete this data at any time by:

• uninstalling the app, which removes all of its local storage, or
• using Settings → Clear history (all results) or Clear all local data (results and settings), or deleting a single result from its results page.

Mobile Castle does not hold a copy of this data, so there is no separate server-side deletion request to make to us.

For data processed by the third parties above (for example Google’s advertising data), please use the controls those parties provide (see their policies linked above) and your device’s Ads settings.

Security

Because DeviceMint keeps your data on your own device and does not run a Mobile Castle server, your test results are not exposed on our infrastructure. Reports leave your device only when you share them.

No method of electronic storage or transmission is 100% secure; while we aim to protect your information, we cannot guarantee absolute security.

Changes to this policy

We may update this Privacy Policy from time to time, for example if the app adds a feature that changes how information is handled. When we do, we will update the Effective date above and post the revised policy at the URL where this policy is hosted. Significant changes may also be noted in the app or its store listing.

Contact

If you have questions about this Privacy Policy or DeviceMint’s data practices, you can contact us at:

• Email: mobilecastle.android@gmail.com
• Publisher: Mobile Castle