I posted this in the games section, but this thread seems alot better suited since its for ideas for apps
Its an unlock achievement system
Similar to the xbox live/wow/lotro/WAR system.
Where doing certain actions talies up and say after 1,000 text messages you get a notification. and then next one being 5,000. and so on.
There could be some prizes, or points gained over time. Who knows, but this could be an interesting concept.