Abstract: The present invention enables a cell phone or PDA user to purchase a full version of an application with a single key stroke, without switching back and forth between the application and a browser. A one click upgrade is made available which is intuitive and quicker than prior methods known in the art. Trial versions in the present invention are full versions with most of the game disabled. Upgrades to the full version are enabled by setting a flag once the customer has paid for the upgrade. The customer is able to play one level or track for a game or to play the,game for limited period of time. Once the trial limit is reached, the content or game provider offers details on how to purchase the full version.