A very small security enhancement has been made for iPhone and iPod Touch applications by Ben Chatelain, developer of the Full Screen Web Browser app who was tired to see his app pirated and available for free everywhere online.
The solution that I came up with is for the app to simply detect whether it has been compromised and to send that data over the wire to our server. All of these simple server pings are logged along with the unique device identifier (UDID) so that illegal usage can be tracked. Then, the server controls a demo period; after 10 runs a message is presented which gives the choice of visiting the Full Screen Web Browser page in the App Store or exiting the app.
Very ingenuous but is this really gonna stop crackers? I doubt it but it is already a first step towards anti-piracy, which I see as a big improvement.