In the sideload-friendly world of android, spyware apps that can track the cameras, microphones, text and call logs, take screenshots, all of this **** can be installed on a non-rooted device and hidden away from view - I just had to help a friend with one of these things on his samsung device. This is impossible on an iPhone without jailbreaking, and jailbreaking causes a number of obvious hints that something is wrong.
So, my concern here stems from if apps can just be installed on my device, and they get full SDK and sensor access... iPhone is going to end up in the same morass as android in terms of trust.