A free program for Android, by Azumio Inc..

Sleep Time: Sleep Cycle Smart Alarm Clock Tracker is an application that is designed to help you sleep better. If you have trouble falling asleep or if you have a habit of waking up at the slightest noise, then this application is definitely for you. Sleep Time will not only remind you to go to bed, but it will also help you fall asleep faster and it will help you wake up more naturally.

The application is very easy to use. First, you have to download the app. Next, set the time for which you want to be waked up. The application will then start to work and will begin to wake you up.