What are some alternatives?
When comparing Sleep Time - Alarm Clock and Sleep as Android, you can also consider the following products
Sleep Cycle Alarm Clock - Bio-alarm clock that wakes you up at optimal times based on your sleep patterns.
SleepBot - SleepBot is a sleep tracking app available in Google Play and the Apple App Store.
Pillow for iOS - An iOS companion that helps you sleep better 💤
Talalarmo - Minimalistic android alarm
Gentle Alarm - Gentle Alarm can consider your sleepcycles to wake you up when you are in light sleep.
Alarm Klock - A better alarm clock.