Very good program
I use wahoo fitness app 5-6 times a week in the summer with my iPhone set up on my bike, blue tooth headphones, and a wahoo heart rate monitor, and I have never had a problem. Easy to configure how you want it, calories, heart rate, cadence, speed, etc... Can even set up voice prompts when reaching mile stones and heart rate levels. I would highly recommend this app. Also I can upload all my data to my iPhone health app, Nike+ fuel app and Strava.
Update: 1 year later: I have discovered the ability to bring up a heart zone page on the app, very happy with this. It shows you all at once what heart rate zone you are in and if its warm up, fat burning, aerobic, anaerobic or speed/power zones. There are visual cues of blue, green, yellow, and red colors behind the heart rate zone numbers as well.
I honestly do not know why anyone would want to run another app or even use a bike computer unless they were going out for a 2+ hour ride. Then it makes since because the battery in the phone does not last much more than 2 hours straight. But WOW is all I have to say, great great app.
Johnny A Smith about
Wahoo