This app was mentioned in 2 comments, with an average of 1.00 upvote
Smart Sleep Manager (link is to Android play store. I would tell you who it is by but it's some kind of Asian characters that I can't read.)
This one is free and allows you to back up your reports to your SD card.
I tried a ton of them but this one was the most accurate.
I have fibromyalgia and chronic fatigue syndrome so it helps me to know how my sleep is going. The reports from when I co-sleeping to now show a huuuge difference. They aren't kidding when they say co-sleeping is good for mom too.
A smart alarm app or device could help a lot. Something like this or a jawbone.