Apple Watch sleep tracker app

Wife gave me an Apple Watch for Christmas. Anyone know of a good sleep "tracker" app? I have downloaded a few but no luck so far. I am really looking for a watch app that has an alarm that will wake me in my lightest sleep cycle along with a graph of somewhat sorta what my sleep pattern is.

Sleep tracker apps don't work.

Check reviews on Engadget.
I use their reviews when researching new tech.

Windcpap agree and disagree. Accuracy nope. Alarm on my wrist that gently wakes me instead of blaring alarm yes. I don't really need a graph. My machine is old and is a pain to get any software on.

Thx chunky frog.

I just really want to try the wake me in my lightest sleep idea. Tried it with my phone last night and was actually very surprised when I didn't wake up like a zombie today.

Actually, if you are getting good deep sleep in the first 1/3, your chances of waking in the lightest part of your sleep are pretty high in the morning. You pretty much finish with stage 3/4 sleep the first half of the night.