I am an avid quatinficationist ��
I have tried the two big ones available right now. Sleep++ and Sleep Pulse.
Sleep++
Pros: Clean and easy to use
Free
Cons: Not detailed enough or sensitive enough
Sleep Pulse:
Pros: Combines heart rate and movement for a more accurate gauge of sleep
.5 increments to adjust sensitivity
Cons: Not super clean looking, but works well. iPhone app provides a lot of information, but not very pretty
$2.99
I have used both for a few weeks and the keeper is Sleep Pulse. With the added accuracy and the ability to increase or decrease sensitivity it is the sleep tracker I am sticking with.