Tap Tap Revenge, a free music game for the iPhone from Tapulous, is the second app to hit one million downloads, according to Tech Crunch. While the Tapulos business model is less direct, other developers are making very good money selling their native apps on Apple App Store.

Tapulous is the developer of the addictive, free app for the iPhone that allows the user to tap through the beats of a song or shake the phone in sync. The Tapulous CEO said that they’ve had about 900,000 downloads so far and expect to hit one million this weekend.

The Facebook app has already hit the one million mark. That’s impressive considering that Apple has only sold about 7 million iPhones to date.

Tap Tap Revenge

Because Apple doesn’t allow developers to access the iPhone’s music library with a native application, Tapulous had to resort to Internet downloads offered by indie music artists -- to the tune of 2.5 million songs downloaded so far. That has turned out to be a serendipitous approach.

As a result, some record labels are taking notice. They’d like to use the app as a means of exposing customers to their music. Tapulous is still working out those details.

While the business model of Tap Tap Revenge may be indirect, some other developers are making very good money with the outright purchase of their apps. For example, according to 9to5 Mac, Eliza Block is earning almost US$2,000/day with a crossword puzzle, 2Across.

While at least one developer has questioned the advantages of native apps from a technical standpoint, the unique capabilities of native apps, their immediate appeal, and the imagination of native developers is driving the App Store to new heights. Some developers are getting very rich indeed, even after Apple’s 30 percent take.