privacy

Probably worth noting that the "approximate" data apps have can be pretty accurate. For example apps can set your cell carrier, strength, and IP which in a city can result in very granular information. Apps can also buy location data from apps which do have your location permissions (like weather apps) and correlate that way. Tim Hortons even sold that exact data to anyone who asked, like car dealerships.

Linking from the phone number or email to secondary accounts is the first thing anyone would try, so I dont think anyone should be surprised or assume that was a lot of work select * from users where phone = 'X' or email = 'Y'would do the trick.

All this is to say, do not ever install an app from a potential adversary.