What are some alternatives?
When comparing Sleep Time - Alarm Clock and Sleep Cycle Alarm Clock, you can also consider the following products
Sleep as Android - Common alarm clocks ignore your sleep cycles, they wake you on schedule no matter your are currently in your deep sleep. Waking up from deep sleep is unpleasant, it makes you tired and it may negatively affect your productivity during the whole day.
Pillow for iOS - An iOS companion that helps you sleep better 💤
SleepBot - SleepBot is a sleep tracking app available in Google Play and the Apple App Store.
Alarm Klock - A better alarm clock.
Sleep Calculator - Want to wake up in a good shape?
EasyWakeup - EasyWakeup is an advanced alarm clock for iPhone/ iPod Touch.