Sleep Cycle - Bio-alarm clock that wakes you up at optimal times based on your sleep patterns.
Do You Even List? - Auto updating Twitter list of people you interact with most
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.
Listr - Listr lets you explore some of the best lists on Twitter, curated across your favorite categories.
Pillow for iOS - An iOS companion that helps you sleep better 💤
Vicariously.io - Create Twitter lists based on the follows of other users