Daily App: Threes! is a tiny puzzler that'll convince you math is cool

Threes! is a game of threes that, appropriately, was made by three people -- Asher Vollmer, Greg Wohlwend and Jimmy Hinson. It's a sliding puzzle game that'll have you doing math and loving every minute of it.

Threes! challenges you to slide numbers together in order to add them, but there is a catch -- the sum has to be a multiple of three. Lower numbers can be added together to equal three or six -- you can add 2 + 1 and 3 + 3, for example. Higher numbers can only be added in pairs -- you cannot add 6 + 3, but you can add 6 + 6 or 12 + 12.

This is a sliding puzzle game, so the tiles shift when numbers are added together and combined into one tile. New numbers are also randomly added to the board and an indicator at the top of the screen shows you which number is coming up next. Your goal is to add as many numbers together as possible and keep the board from filling up. Once you can no longer add any numbers, the game is over.

There's a twist in Threes! that makes it a bit more challenging than most puzzle games that I've played -- instead of sliding one square at a time, the squares slide in groups. When you try to add 3 + 3 at the bottom, you may also be adding a 2 + 1 at the top. It makes the strategy that much more difficult when your moves have multiple effects on the board. The trailer above shows the gameplay, but you really have to play it yourself to get the feel of it.

Threes! is one of those games that is easy to pick up and addictively fun. The graphics are appropriate for the game and the music in the background is just perfect -- it's catchy enough that you hear it, but subtle enough that you don't focus on it. There are also voiceovers that provide the tiles with some character -- literally. Each block has a personality with a small face and a tiny voice that responds when you touch it.

Threes! is available in the App Store for US$1.99 and is worth every penny. Puzzle fans should just go and buy it now. You won't regret it.

A quick note for parents who are buying it for kids. Threes! would be an enjoyable game, but it's not meant for the younger set. The app has a prominent tweet button, an easily accessible credit screen with links to the developer's Twitter accounts and an App Store link for the developer's other game.