From Leonardo: (obviously, his first language isn't English, but bear with him)
One of my favourite apps in Android is Sleep as Android, an app that monitors the accelerometer when you are sleeping and, based on that, it determines when is the best time to wake you up in a predefined time interval (because sleep more do not means wake up better). If you want you can read more information related to REM periods and so on in the developer's site.
What I can tell you is that I've been using it since too many time ago and definitely it works. Unfortunately is not available on Symbian, but I want to get rid of my Android tablet so... I decided to develop the app for myself!
The app I've done monitors the accelerometer sensor, makes some algorithms and keeps the data in a file in "E:\wakeuphealthy" folder. My idea is that people with different phones (I only tried it in my Nokia 808) can test it and give me some feedback so I will know if there are differences in sensors and also get stats to define the best threshold, configurations, ui, etc
Hence if anybody wants to test this "pre-alpha" app, follow these steps:
Here's (part of) a sample of Wake Up Healthy's output, analysed in Excel on the desktop:
The periods where the records are below the improvised red line are the "deep sleep" phase, and the peaks are the points that are supposed to be good for waking up.
Comments welcome, but please also copy the developer in by email at email@example.com.