Lobs a grenade: http://www.securityweek.com/apple-yanks-privacy-app-app-store

As screams of "Unbeliever! Unbeliever in our midst!" ring out, sneaks out...

Why did they pull it?

Um, probably due to blatant use of undocumented APIs to pull off these functions? An app cannot get information on other apps on the system using official APIs. That's a security feature, I am actually quite surprised they were able to do this at all (even ignoring Apple APIs).

I think it's a good thing if the scare ware stays off iOS devices. Bad enough they're duping millions of Windows users all over the world.

What is scareware?

Scareware is when I release an iPhone app called "ANTI-VIRUS SECURITY SUPER LOCK" that costs 99 cents and does absolutely nothing except throw up scary looking dialogs and red buttons. Technically, it would "work" because there is no malware for iOS so my software would ensure you remain malware free.

That's exactly what a lot of Windows software does...

And that's exactly one case where Apple's tight control of the app store is a good thing. Not saying theres no downsides, but this is one of the upsides.

Allright so here is how they do this:

http://www.iphonedevsdk.com/forum/iphone-sdk-development/37103-finding-out-what-apps-installed.html

And yes, doing this does violate the app store rules. As it should.

Once you have a list of installed apps, you don't need to "scan" to see what they are doing - you can't, that's not possible due to security restrictions on the phone. But what you could do is send the list back to the server, and the server could have a database where things like "accesses location", "accesses address book" and so on are noted. They could even automate generating this database using a jailbroken iPhone which records what app is doing what (something you can't do on an un-jailbroken phone).

Sorry for the tech babble, was just interested in how this would even work.