The easiest way in isn't even writting an app, just provide a dylib that solves a common problem, get it into an answer on a site like StackOverflow and you now

The easiest way in isn't even writting an app, just provide a dylib that solves a common problem, get it into an answer on a site like StackOverflow and you now can run whatever you want on plenty of devices. Remember Apple doesn't instrument the Apps when they review them, the closest they come to that is running everything through a proxy and looking for connections that are obviously malicious. This is one of the massive holes in the wall that Facebook often walks through.