It's happened to just about everyone who has bought an iPhone application at the iTunes Store: At some point the application you paid $7.99 for goes on sale for $1.99--sometimes it's even free the next day. I've had this happen to me many times, but only because it's part of the job to get applications when they're hot off the presses. Fortunately, as part of the job, I don't have to (personally) pay for the applications I review. Most people aren't so lucky.

Fortunately, an application made for bargain hunters that had been sitting in Apple's queue for several weeks (deemed by the development team a "pocket rejection") finally made it to the iTunes Store. Nobody knows why Apple was holding out, but now that it's here, I think most people will want to download it.

This week's apps include an iPhone application bargain finder program and a zombie-themed tower defense strategy game.

Sort through specific categories or just find the best bargains for all applications. (Credit: CNET)

BargainBin helps you save money on iPhone applications by automatically finding deals on applications as they happen. A lot of iPhone application developers have recognized the advantage of selling their applications for a lower price either initially, or to generate interest in their application for a short time at the iTunes Store. BargainBin scans the iTunes store for these changes in price, helping you find applications that you might have thought were previously too expensive. You can sort by category and then use the buttons at the top of the interface to find bargain prices or applications that have since become free. Nobody wants to spend top dollar for applications if they have a choice, and this application is the perfect way to find deals at the iTunes Store.

Zombie Attack Free
As you gain levels, more zombies slowly come at you as you try to defend your simple shack (Credit: CNET)

Zombie Attack Free is the free version of the full tower defense strategy game, Zombie Attack. Like other real-time strategy games, you need to fight off a horde of baddies with strategically deployed gun turrets. But in Zombie Attack, an endless stream of zombies (punctuated by progressively more difficult levels) rush across a field, trying to reach and attack your humble shack, as you run around on the field (by tilting your device) placing and upgrading gun emplacements. You earn money for every zombie you drop, and the game ends when the zombies destroy your shack. The paid version (gives you several guns to choose from including flamethrowers, saw blades, and more. If you can't get enough of tower defense games (like me) you will like the unique strategy of this game.

What's your favorite new iPhone application? Have you found any bargain basement prices in BargainBin I should know about? What's your favorite tower defense game? Let me know in the comments!

Jason Parker has been at CNET for more than 13 years. He is the Senior Editor in charge iOS software and has become an expert reviewer of the software that runs on each new Apple device. He now spends most of his time covering Apple iOS releases and third-party apps.