A Soft Murmur - Ambient sounds to wash away distraction.

Sleep Cycle - Bio-alarm clock that wakes you up at optimal times based on your sleep patterns.

Rainy Mood - Rainy Mood is the world's most popular rain simulator. Sleep, study, and relax with the sound of rain.

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.

Noizio - Feeling that the noise of the big city is too much for you to bear?

Talalarmo - Minimalistic android alarm