Meet the Wahoo TICKR FIT: a heart rate armband that combines with your iOS/Android device to track your workouts. It has Bluetooth and ANT+. It works with third party apps on your smartphone and tablet. TICKR FIT works with Strava, Runkeeper, MapMyFitness, and other apps.
TICKR FIT has a rechargeable battery that lasts over 30 hours. It is adjustable and doesn’t get in your way. Costs under $80 at this time.