Many a time when I've been lying in bed, waiting for my body to enter a state of slumber, I often think to myself: 'Why isn't there a turn-based card game that also brings in elements from hit gameshow Countdown?'. It's a question that has never been answered... until now.

From the mind of SeanBaby - internet humourist and frequent contributor - Calculords is a simple setup made incredibly addictive thanks to the addition of... a calculator. All the usual staples are here - you'll build a deck consisting of different cards, each with their own abilities - and the sole idea is to fight your way to the enemy's base and destroy it.

It's nothing you haven't seen or played before, but the addition of maths does, somehow, add to the overall experience. You can only place a card if you have the corresponding number in your inventory. Often you may luck out and find yourself gifted with such a number, but if not it's off to your trusty calculator to try and get the figure you need.

On occasion you'll genuinely need to test your own intelligence to succeed, and there's the ongoing dangling carrot that if you manage to use all the numbers in any given round, you'll be treated to a Calculords bonus. Considering that maths sucks, it makes the whole concept even more satisfying.

It's a unique twist on a familiar idea - it does make the whole back-and-forth card battling concept far more interesting, however. Throw in that it's free and the in-app purchases aren't the epitome of slapping your mother in the face, and Calculords is one of those games that restores your faith in mobile titles. If the likes of Candy Crush makes you want to kill yourself...

Version tested: iOS on iPhone 5. Played for 3 hours.