Have you ever woken up feeling completely wrecked when the alarm clock goes off, despite the fact that you have slept "enough" hours? Yet other days you spring out of bed with a smile on your face, feeling completely rested even though you shouldn't?
During the night you go from light sleep to deep sleep, occasionally entering into a dream state which is called REM-sleep. These are things that your normal alarm clock does not care about, and will go off at the set time regardless of whether you are in a light sleep phase or in the deepest sleep.
However, since you move differently in bed during the different phases, the Sleep Cycle alarm clock is able to use the accelerometer in your iPhone to monitor your movement and determine which sleep phase you are in. Sleep Cycle then uses a 30 minute alarm window that ends at your set alarm time and wakes you in your lightest sleep phase.
Sleep Cycle also saves your sleep data and displays a detailed sleep graph and sleep statistics for every night you use it.
To wake up feeling rested EVERY morning, you can download the Sleep Cycle Alarm Clock in the App Store.