Android: Did you wake up this morning feeling awful, even though you got plenty of sleep the night before? You may have woken at the deep end of your sleep schedule. Sleep Time Alarm Clock is a free app for Android that will make sure that doesn't happen again.
Sleep Time is the most advanced sleep tracking app for Android we've seen. The app sits in bed with you (so make room!) and uses your phone's accelerometer to detect your movement over the course of the night. It then charts that movement to determine which phase of your sleep cycle you're in at what time of night.
You can use it just to analyse your sleeping patterns and movements, but it really shines when you set an alarm. The app will wake you at the lightest part of your sleep cycle, so you don't want up feeling ripped out of a deep sleep. If the app detects you'll be in a deep sleep at your alarm time, it will wake you a little sooner so you don't feel groggy when it's time to get up.
Granted, Sleep Time can't compete with some of the more high tech methods we've covered, but for the low price of free, it's worth a try.