Bodyweight-only exercises have greatly picked up in popularity over the past couple of years and have been proven to provide excellent results.
Jumping rope has long been a staple of many athletes resulting in fat loss, increased cardiovascualr conditioning, and well as improving overall muscle tone.
Jump Rope Time is a counter that uses advanced algorithms to count your jumping activity. The clean and simple interface make it easy to use. Just strap your device on your arm using one of the many iPhone armbands that are available, hit start and get to work.
Audible feedback is provided as well.
Please also see other exercise applications such as Its Pushup Time, and Sit Up Time.