How is an iOS app on the App Store able to detect other apps?!?!

A client asked why we can't detect other apps installed on a device without an MDM profile, we explained this isn't possible due to privacy and security restrictions on iOS. A regular app cannot find other apps that are installed unless part of the same group.

The client then told us to download SpyBuster (on the App Store) which somehow is collecting a list of Bundle IDs or names of all installed apps somehow.

We were skeptical, but sure enough, the app showed us a list of apps we had installed. How is it doing this?!?! No MDM profile associated with the app. No special permissions requested. No access to anything shown in privacy & security in settings.

Is there a special entitlement we're not aware of?

Just seems like they must be using a private API call to get this info but that would of course mean it should be pulled from the App Store. We'd love to have this capability in our apps if it's legit and accepted by App Store review.

Thanks!

They can use the app delegate can open url to find some apps. https://developer.apple.com/documentation/uikit/uiapplication/1622952-canopenurl

There are limits on it for privacy reasons.

How is an iOS app on the App Store able to detect other apps?!?!
 
 
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