Let me introduce my first Android application:
Rooster is a alarm clock designed for all those people that snooze their alarm endlessly and it also includes a Timer and a Stopwatch.
You can develop and publish your custom challenge using Rooster API and sell it independently on the Market.
More info at: http://www.e-intents.com/rooster
Rooster API: http://www.e-intents.com/rooster/api
Comments, suggestions and bug reports are more than welcome!