If you're on the lookout for a fun and casual puzzle game, you may want to consider free-to-play title Quads.

Quads is a game all about sizes. In each turn, you're presented with a 10x10 grid of green, red, blue, and purple squares. Your aim is simply to tap on the colour that covers the most squares. It's really that simple.

Each time you successfully tap on the largest area and earn points, the on-screen colours shift and move around on the game board. You repeat the process until the in-game timer ticks down to zero.

You can spend the points (known as quads) you earn as you play in the in-game shop on a range of power-ups that enable you to - among other things - extend the abovementioned timer.

Quads isn't like a lot of the puzzle games on the App Store.

Your main aim in Quads, you see, isn't to bag yourself a high score that you can show off to your friends down the pub. Your aim is simply to have “fun” while you play.

“While the player concentrates on the game and enjoys the sounds and atmosphere, he / she should fall into another world and just become relaxed. I think this is different from most other games in the App Store,” Marcus Dobler, Stars Projekt & Event's CEO, said.

“I'm proud of the animation in conjunction with the sounds. It took me a long time to get Quads to look and feel like it does, but I'm pleased with the overall look and feel of the game!”

Dobler plans to extend the life of Quads via content updates. In the first of these updates (which is already on its way), Dobler's team will introduce a brand-new game mode called Memory. You'll be able to unlock it via a single in-app purchase.

In Memory mode, each coloured area of the 10x10 grid will instantly disappear from your screen as soon as the game board is fully constructed. In other words, you'll have to choose the largest area completely from, well, memory.

Naturally, this is a lot harder to do, but you'll be rewarded for your efforts with extra points for each round you manage to complete before the in-game timer counts down to zero.

Further updates will contain new sound packs.

You can download Quads exclusively from Apple's App Store completely free of charge. If you're itching to spend a bit of cash, however, you can spend some of your hard-earned pennies on extra quads, which will enable you to purchase extra power-ups.

These power-ups will make your journey to an impressive high score a lot easier, but they're far from essential. Dobler believes that gamers should be able to play for free, and only put their hand in their pocket “if they're ready to pay”.

This is why the free-to-play model was the only model that Dobler considered during the development of Quads.

You can grab Quads from the App Store right now for free [download].