MacHeist is back, with a new Heist (rather than a Bundle). This time, however, the Heist is in the form of a new iPhone app instead of being on the website.

For those of you who are new to MacHeist, they do a couple of things. They do occasional bundles of Mac software, which are great deals usually. (They make deals with various independent developers based on the principle that tens of thousands of sales at a much reduced price is better than a few sales at full price.) And the other event they hold is something they call a Heist. When they do a Heist, they have a series of clues and puzzles scattered around their website—a treasure hunt of sorts—that allow you to unlock software licenses as you progress through them.

The new “The Heist” app costs $0.99 in the App Store, and it’s basically a collection of puzzles. There are four varieties, and many different difficulty levels for each one. As you solve more of them, you turn off the various security systems protecting the vault displayed onscreen. Once you have enough done, you can unlock the license to a secret software package.

The puzzles start out simple, and quickly progress to a fairly frustrating level. I haven’t managed to unlock the vault yet myself, so I can’t speak for the quality of the vault’s contents, but the app is entertaining in itself.

Oh, and if you tweet about the new app, you could win one of ten limited-edition iPads.