Your iPhone Could Be Hacked by a Simple Free App

I happened to come across the following video recently, which talked about have your iPhone could be hacked by a simple free app, like a flashlight app. Once the malware gets in, it can access everything you have on your phone.

First of all, is this real or BS? Any experts out there that know whether this is true or not? I've heard strong opinions on both sides.

The guy being interviewed talked about a quick and dirty way of checking to see if the app you installed could be a trojan. He said that if it takes up more than a megabyte, there could be a problem, because why would you need that much memory to just show a blank screen.

I actually have a free flashlight app on my iPhone, which only takes up around 80k. However, I noticed that there is an update for it that is 8 megs. What could a flashlight app possibly provide that would take up that much memory. I can already have my phone display different colors and flashing colors. So I think I will hold up on getting that update.

If what this guy is saying is true, is there a malware protection app that would stop any bad apps from even being downloaded? If so, can anyone recommend one?