The Sleep Cycle Alarm Clock analyzes your sleep through your movement, and wakes you up at a time that is optimal for your sleep schedule. This app lets you set a time interval that you would like to wake up during, and tracks your movement to choose the time when you are in the lightest phase of sleep, allowing you to wake up more refreshed and energized. I’ve used this alarm in the past and it has been helpful, but I found that it does not work well under sleep-deprived circumstances (In situations when I have been sleep-deprived, I often found myself snoozing it to get more sleep instead of waking up at my optimal time). However, it is a great and innovative tool, and also allows you to better track your sleep and sleep quality.