One of the more high profile pulls in App Store history, Nullriver's NetShare enabled users to use their iPhones as cellular modems. While this feature later made its way into the iPhone OS in version 3.0, it's not available on all carriers--most notably on AT&T in the U.S.
The app originally showed up in the App Store July 31, and was pulled shortly thereafter. It then reappeared the next day before once again being yanked...this time for good. Those who still have the application may not see future updates, but it still works on the latest firmware.
Software maker Nullriver continues to write software for Mac, Windows, and the iPhone and still has two other applications on the App Store: Aquanotes, which lets users remotely monitor aquarium information, and Tuner Internet Radio, a streaming radio app.