For the people who have this issue, I cannot recommend sleep as android (android only) highly enough, especially if you have a smart watch with heart rate monitoring.
I set an alarm for 07:00 and it wakes me up between 06:30-07:00. But it does so in the best phase of your sleep, so you feel wel rested.
Also I have it set to vibrate my watch, instead of making noise. And I love it.