Nobody asked your phone for this.

Asked here, before you have to ask them

What does my phone know about me?

More than any one permission covers. The six lines at the top of this page came from your browser with no prompt, and an app you install can read a good deal more. The useful question is which of your apps carry trackers, and how far those trackers can climb. That’s what the app shows you, one app at a time.

Is my phone tracking me?

Some of your apps almost certainly carry tracking code, in the ordinary advertising and analytics sense: code from a company other than the one that made the app. That’s a different thing from a person following your location on purpose. This app is about the first kind, and it tells you which apps carry it.

How do I reset my Android advertising ID?

On most Android phones it’s in Settings, under Privacy, then Ads. Newer versions let you delete the ID outright instead of resetting it. Phone makers move it around, so if it isn’t there, search Settings for “ads”.

How do I stop apps tracking me on iPhone?

Settings, then Privacy & Security, then Tracking. Turn off Allow Apps to Request to Track and new apps get told no without asking you. Apps you already said yes to are listed right under it, and you can switch each one off.

Does it need permissions?

On iPhone, one: notifications, and only if you tap Remind me in a week. On Android, four, and all four are there for the ad: internet access, network status, the advertising ID, and one that keeps the phone awake while a request finishes. No location, no storage, no contacts, no camera, no microphone on either. The scan itself needs none of them. That’s a short enough list to check rather than believe, and the Android build fails if a library slips anything else in.

Why does this page have ads?

Because an ad is the quickest way to watch all of this happen, and describing one is a poor substitute for showing you. The Android app carries one for the same reason. The iPhone app has no ad yet, so it walks through an ad request field by field instead. Here the Ads section at the bottom lists what your browser sends to get one, with your own values filled in.

Does it send anything anywhere?

Nothing comes to us. There’s no account and no server on our end, so there’s nowhere for your scan to go even if we wanted it. The iPhone app doesn’t connect to the internet at all, and its App Store label says Data Not Collected. On Android the one thing that goes out is the ad, and only after you tap for it: that sends and receives the basic metadata an ad request runs on, and the app lists every piece of it on screen before you ask. Android apps have to declare network access before they can use it, so you can check the whole list against the file in about ten seconds.

Is this an anti advertising app?

No, and it would be a worse app if it were. Plenty of people prefer ads that match what they’re interested in. The point is knowing what gets made and how it combines, not being told how to feel about it.

What does it cost?

Nothing. There is no subscription, no upgrade and no account to make.

What can it not see?

On Android, apps without an icon in your launcher, which includes most of what the manufacturer preinstalled. And anything a tracking library does at runtime, because reading code tells you what is in an app, not what it did this morning. On iPhone it’s the opposite problem: it only knows what Apple’s report recorded, so it needs about a week of recording before there’s much to read. There’s a sample built in so you can see what you’ll get first.