This app, one word: AWESOME. It wakes you up within 20 or 30 minutes of your alarm(you choose) to wake you up in the lightest stage of your sleep cycle. Freaking amazing. You set your phone on your mattress and then voilà you wake up in the morning to your alarm but feel like you should have woken up! It's awesome and I hate to alarm without the sleep tracking now.
I choose to scan a QR in the morning to turn off the alarm, it's on my doorknob.
Also, you have the option to snooze or dismiss the alarm. If you snooze it you can choose for how much amount of time, 1 minute, 5 minutes, 10, 15, or 20.
Best app ever. 14 day free trial but I paid the $2.99 for the unlock because I felt so much better.