Apple has added the ability for an app to ‘upcharge’ inside of the application. The first thing everything thinks of is games, where you could buy levels as you move through the game.
Two apps that I have used the In-Application upcharge in a different way.
IDEO has an application called Method Cards – a electronic version of their deck of printed cards to help getting creative energies going on a project. IDEO’s application is downloaded for free, but contains only 8 of the full deck.
This gives the user a chance to play with the product for a while without installing a ‘lite’ free version then returning to the iTunes App store to buy the full version. In the case of the Method Cards app, all of the cards are installed but not viewable.