This ransomware acts as a porn app named "Adult Player" and lures victims who assume it is a pornographic video player. When the victim starts using it, the app silently takes a photo of the victim, which is then displayed on the ransomware screen, along with the ransom message. The app demands a ransom of 500 USD.

http://research.zscaler.com/2015/09/...ansomware.html

Just looking around that site there's more of this type of malware than I would have thought. I don't add any apps to my phone except those that are needed to use it as a phone/texting device so I've been blissfully unaware of the magnitude of the problem.