^^^ Add Cyclemeter to the list when trying out apps. It's pretty clean and, while extremely feature rich, it doesn't give you a cluttered screen and isn't really geared for competition, although you can use some of it's features to do so. And since the phone you have is a 4S, it can use BTLE sensors, like those provided by Wahoo, to give you speed, cadence and heart monitoring and it's compatible with the RFLKT.