Exercising with your iPhone or Android device will be much more convenient when you have one of these fitness cases. You could always use a traditional armbands, this case lets you use your phone when you are training. You will have a much easier time answering calls and getting things done on your phone when you are exercising.
You will be able to run, do push ups, and a whole lot more when you have one of these on. The GoCuff comes in three sizes. Perfect if you are tired of traditional armbands. This project is being funded on Kickstarter at this time.