In the past few years, we have covered a whole host of iPhone compatible exercise bikes here. The Vive Smart Magnetic Pedal Exerciser is also worth a look. It is a mini exercise bike with app connectivity. It measures only 11 inches in height, so you can fit it under your desk to get a workout at work or home.
This mini exercise bike has a LCD display to show time, distance, speed, and calories. The companion app lets you take scenic tour workouts and track your stats. The bike has non-slip pedals for a safe workout. You can not only use it to work your legs but also your arms on your desk.[where to get it] [app link]