"Sleep Cycle" is currently the ninth most popular App in the US, and the #1 app in nearly a dozen countries. The app uses the iPhone's motion sensor to track how well you sleep at night.
WFFT teamed up with Parkview Hospital's Sleep Disorder Center to see whether the app was accurate. WFFT's Robert Bumsted spent a night at the center attached to the hospital's sleep monitoring system.
After eight hours of sleep, the Sleep Disorder Center says the app was relatively accurate. Medical Director Srinivasan Devanathan says the app was generally able to determine periods of light sleep versus periods of deep sleep.
Doctors warn, however, that the app isn't accurate enough to be able to diagnose real problems. If you think you may have a sleep disorder, the best route is to contact your physician.
You can check out Sleep Cycle for yourself on the Apple App Store by clicking here.