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Privacy Policy

Effective Date: September 23, 2026 · Last Updated: October 4, 2026

Trei ("we", "us", "the developer") publishes mDevices, a family location-sharing and device-finder app for Android and iOS. mDevices and mFamily are the same app under two names. This policy explains what the app collects, who can see it, how long it is kept, and how to delete it.

The short version: mDevices collects the precise location of each device you sign in on, including in the background, and shows it to you and to family members you have linked with. Location is reported about every 30 minutes in the background, when you open the app, and when a linked family member asks for a refresh. It is stored on our servers until you remove the device or delete your account. We do not sell your data, and location is never sent to ad networks or analytics services. Free-tier users see ads; Premium removes them.

Data We Collect

Location data

Location Data Disclosure mDevices collects precise GPS location from each device you sign in on, including when the app is closed or not in use (background location). This is the core purpose of the app. Each location report contains:

Latitude and longitude - the precise coordinates of the device.
Accuracy, altitude, speed and heading - as reported by the phone's location service.
Timestamp - when the reading was taken.

How often - about every 30 minutes in the background (Android and iOS may delay this to save battery), whenever you open the app, and when a linked family member asks your device to refresh its location or ring.
Foreground location - collected while you are using the app.
Background location - collected only if you allow location "All the time" (Android) or "Always" (iOS), so a lost device can still be found and your family sees a current position. The app explains this and asks for your agreement before requesting the permission.

Account information

Sign-in details - name, email address, profile photo link and user ID from Google or Apple sign-in (Firebase Authentication). Guest mode creates only an anonymous user ID.
Subscription status - Free or Premium, managed through RevenueCat.

Device information

Device details - device name and type, manufacturer and model, OS version, Android ID, battery level and charging state, storage, memory, processor and sensor details, network type, mobile carrier name, SIM country and IP address.
Installed apps (Android) - the list of apps that Android lets the app see on the device (app name, package name, version and install/update dates), sent with the device details.
Push notification token - a Firebase Cloud Messaging token used to deliver alerts and ring or refresh commands.

The app does not read your contacts, messages, call logs, photos, IMEI or SIM serial number.

Family and care information

Family links - the email addresses you send link requests to and the accounts you are linked with.
Saved places, SOS alerts and geofence alerts - including the location attached to an SOS.
Care information - any medication reminders, doctor appointments and care notes you add.

Usage, diagnostics and advertising data

App interactions - screens viewed and actions taken, collected with Firebase Analytics, Meta App Events and our own analytics server, to understand how the app is used.
Crash logs and diagnostics - crash reports and error reports (Firebase Crashlytics and our own error log).
Advertising ID - used by Google AdMob and Meta Audience Network to serve ads to free-tier users.

How We Use Your Data

Data	Purpose
Precise and background location	Show each device on your map and your linked family's map, find lost devices, SOS and geofence alerts
Account information	Sign you in and let family members find you by email
Device information and installed apps	Show device status and details on the device screen for you and your linked family
Push token	Deliver alerts and ring or refresh commands
Family and care information	Share links, alerts, reminders and care notes with the family members you choose
App interactions, crash logs, diagnostics	Analytics, fixing bugs and improving the app
Advertising ID	Serve ads to free-tier users

Who Can See Your Data

You - your devices, their latest location, device details and location history.
Family members you link with - linking needs both people: one sends a request by email and the other accepts it in the app. Once linked, each person can see the other's devices, including latest location, battery level and the device information above, plus SOS alerts, geofence alerts and shared care information. Either person can unlink at any time in the app, which stops the sharing straight away.
The developer - stores the data on our own servers to run the app.

Your location is never sold and never sent to advertising networks or analytics services.

Location Permissions

Background Location Disclosure mDevices uses ACCESS_FINE_LOCATION, ACCESS_COARSE_LOCATION and ACCESS_BACKGROUND_LOCATION on Android (and "Always" location on iOS) to report the device's location while the app is closed, so a lost device can be found and linked family members see a current position.

Stop background collection: set location to "Only while using the app" in your phone's settings.
Stop all collection: set location to "Don't allow", remove the device from your account in the app, or uninstall the app.
Stop sharing with a family member: unlink them in the app.

Third-Party Services

Firebase (Google) - sign-in, push notifications, analytics (app interactions) and crash reporting. Firebase Privacy Policy.
Google AdMob (free tier) - receives your advertising ID, IP address and ad interaction data to serve ads. Google Privacy Policy.
Meta Audience Network and Meta App Events - Audience Network serves ads to free-tier users and receives your advertising ID and ad interaction data; App Events receives app install and usage events to measure ads. Meta Privacy Policy.
RevenueCat - Premium purchases; receives your app user ID and purchase receipts. RevenueCat Privacy Policy.
Sign in with Google or Apple - Google, Apple.

We also disclose data if required by law or legal process.

Data Storage and Security

Data is stored on our own servers (Node.js with MongoDB).
Data is sent over HTTPS (TLS encryption in transit).

No method of storage or transmission is 100% secure, and we cannot guarantee absolute security.

Data Retention and Deletion

The server keeps each device's latest location, which is replaced by every new report. Location history records and device information are kept until you remove the device or delete your account. There is no automatic expiry.
Remove a device in the app to delete that device, its device information and its location history from our servers.
Delete your account in the app (Profile > Delete Account) to delete all your devices, their location history and your sign-in account.
To delete everything else (your profile record, family links, saved places, SOS alerts and care information), or to request deletion without the app, email contact@trei.dev from the email address on your account. We will delete it and confirm by email.
Data stored only on your phone is removed when you uninstall the app or clear its data.

Children's Privacy

mDevices is not directed at children under 13, and we do not knowingly collect personal information from them. If you believe a child has given us personal information, contact us and we will delete it.

Your Rights

Access the data we hold about you, including your devices and location history.
Request correction or deletion of your data.
Revoke location and other permissions at any time in your phone's settings.
Opt out of personalised ads in your device's ad settings.

Changes to This Policy

We update this policy when the app's data practices change. Changes are posted on this page with a new "Last Updated" date.

Google Play Data Safety Summary

The Android app and the services it uses collect the following. This matches the Data safety section shown on Google Play.

Device or other IDs. An app-install or device identifier is sent to api.trei.dev once a day to count active devices, and the ad networks may read your advertising ID to show and measure ads.
User IDs. If you sign in, your account ID is used to keep your data with your account.
App interactions. Events such as opening the app or a screen are sent to Firebase Analytics and to api.trei.dev to understand usage.
Crash logs and diagnostics. Crash and performance data is collected to find and fix problems.
Purchase history. Google Play and RevenueCat process Premium purchases and tell the app whether Premium is active.
Approximate location. The ad networks (Google AdMob and its partners) may estimate your region from your IP address to show and measure ads. The app does not use this for anything else.

This data is encrypted in transit. Ad, analytics and crash data is shared with the providers named in this policy for advertising, analytics and fraud prevention. We do not sell it.

Contact

For questions or concerns about this privacy policy, contact:

Trei
Email: contact@trei.dev
Phone: +91 85500 77767
Website: trei.dev · Contact form