Cellphone apps are fun and can help you be more productive, but they also have the potential to be malicious. Make sure you use due caution before installing these apps on your phone (just as you should on your PC). Check out this article on tested.com that gives some tips for spotting fishy apps: http://www.tested.com/news/how-to-spot-scams-and-malware-apps-on-android/862/
Android is the subject of the article, but there is a chance that this could happen to iphones or other smart-phones.
Remember, be safe out there… even on your cellphone.