In the course of reporting my feature story on apps for the Web and mobile phones, I asked developers how much money these little pieces of software are actually bringing in. While they are certainly the exception in the sea of 80,000 programs on Apple?? App Store, I found several apps that have racked up sales of $1 million or more. Here they are:

Enigmo

Sales: $2.5 million

Company: Pangea Software

F.A.S.T.

Sales: $1.8 million

Company: Social Gaming Network

Ocarina

Sales: $1.3 million

Company: Smule

I Am T-Pain

Sales: $1.1 million

Company: Smule

Roller-Coaster Rush

Sales: $1.1 million

Company: Digital Chocolate

Flick Fishing

Sales: $1 million

Company: Freeverse

Ragdoll Blaster

Sales: $950,000

Company: Backflip Studios

Currently, the lion?? share of app revenues come from the upfront fees paid by users upon download. But many developers see much bigger potential with in-app purchases, such as the extra songs you can buy after you download Smule?? I Am T-Pain.

Apple recently lit a fire under this opportunity by making it possible for companies to offer in-app purchases within free programs. Kleiner Perkins-backed game maker ngmoco plans to give away the first level or portion of all its games and charge users to keep playing.