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.

Choosing to ‘Purchase the Full Deck’ results in a box asking to verify the purchase prior to payment. Interesting is that you are not required to put in your iTunes account password again. While this makes it zippy to pay and gain access to your product, I can see this being a possible issue if this was a game and you were buying levels. Let someone play a game on your iPhone, when you get it back you have more levels and a charge on your credit card without needing your permission.

After the purchase, the option to purchase goes away and your off doing a better job of creating the perfect product for your clients.

Another app that uses the upcharge is GoodReader. This application allows a user to read many different kinds of documents.

Where GoodReader used the In-Application charging is for features such as being able to manage your files via Google Docs or FTP.

This method of updating functionality is handy, but for GoodReader has drawn a lot of negative reviews. The features you can upgrade to where previously listed as soon to be added features, which may have encourages some people to buy. Now they are stating it wasn’t mentioned those updates would cost more money. Lessons learned for developers – this functionality is a great way to charge for version feature adds but be sure you have spelled out which new features not yet in the application will cost more.

One way to lesson the negative press, GoodReader added some of the features in a limited fashion to the Lite version to test prior to purchase – but isn’t that just like have two apps that is what In-Application Charging supposed to be trying to do without?