What App Developers Can Actually See About You

When you install an app, the permission prompts are only part of the story. Developers — and the advertising companies whose code they bundle — can gather more than most people realise, and less than the scare stories claim. Here’s the accurate picture, and how to limit it.

The obvious layer: permissions you grant

The clearest data source is whatever you allow: location, contacts, camera, microphone, files, SMS. This is why permission hygiene matters so much — see how to check what permissions an app really needs. Grant narrowly and you cap the most sensitive access at the source.

The quieter layer: data that needs no permission

Some information is available without any prompt, because it’s not classed as sensitive:

• Device details — model, Android version, screen size, language, carrier.
• Rough location — your IP address reveals an approximate region (city-level), no GPS needed.
• In-app behaviour — which screens you open, what you tap, how long you stay, whether you bought anything.
• An advertising ID — a resettable identifier used to link your activity across apps for ad targeting.

The hidden layer: third-party SDKs

Most free apps bundle third-party code — advertising and analytics “SDKs” — to make money and measure usage. These SDKs can collect device and behavioural data and send it to ad networks and data brokers, sometimes across many apps at once. This is frequently the real reason a simple free app wants broad access: not the app itself, but the ad code inside it. The Play Store’s “Data safety” section (on each app’s listing) is where developers must declare what they collect and share — worth reading.

What developers generally can’t see

Android sandboxes apps, so by default one app can’t read another app’s private data, your messages in other apps, or files you didn’t grant access to. It can’t use your camera or mic without the permission and (on modern Android) without showing an indicator. Denied permissions genuinely block access — the system enforces it.

How to limit what they see

• Grant permissions narrowly and prefer “only while using the app.”
• Reset or delete your advertising ID: Settings → Privacy → Ads.
• Read the Play “Data safety” label before installing; prefer apps that collect less.
• Use Data Saver and restrict background data to limit constant phone-home.
• Favour reputable or open-source apps, which tend to bundle fewer trackers.

And the biggest single risk-reducer: install from official stores. A sideloaded APK can bundle whatever it likes with no store review — one more reason to skip unofficial “Aavot APK” files and wait for the real app.