What are some alternatives?
When comparing Gentle Wakeup and Free 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.
Gnome Clocks - Clock application designed for GNOME 3
Sleep Time - Alarm Clock - Sleep Time provides insight into your sleep patterns. By tracking your level of movement throughout the night, Sleep Time generates customized sleep data in easy-to-read charts.
Talalarmo - Minimalistic android alarm
Alarmy - World's most annoying alarm app
Insane Alarm - Wakes you up no matter what! Features - obscenely loud blaring emergency alarm sound.