One of the positive effects of Apple's recently introduced App Store guidelines is that there have since been a handful of applications that have made their way back after initially having been pulled or removed. The latest of that bunch is Infinite SMS, which is currently in review with Apple.
The thing is, Apple never pulled Infinite SMS. You can blame Google for that.
Infinite SMS shot to popularity when it offered a free text-messaging tool that had been built off of Google's Talk service. Not intending Talk to be used that way, Google ended up shutting down access to that data path, leaving the developers of Infinite SMS with a conundrum: do they build up their own SMS service and start charging users for it--thus canceling out any benefit over using the carrier's SMS service, or simply call it quits? The company ended up going with the second option.
Something that could have saved the app would have been be to use Google Voice, which also offered a free SMS tool. But at the time, Apple was not approving Google Voice apps, and the Google Voice service itself was still very much in private beta, limiting how many people could actually take advantage of it.
Fast-forward to now, where Google Voice is completely open (to those in the U.S.), and a handful of Google Voice apps can be found on the App Store, making room for Infinite SMS to make its return. During the year-and-a-half hiatus, the app has been updated to work with iOS 4. Infinite SMS is not coming out of the gate with push notifications, but the app's developer says that this initial version makes use of iOS 4's task completion feature to update you with an alert about new messages for 10 minutes after you last used it.
Related: How to text without a cell phone
Update at 8:40 a.m. PDT October 14: Infinite SMS has been approved by Apple and is available on the App Store for 99 cents.