If you're in the mood for something a simply-designed puzzler to exercise your brain take a look at Invert, out now on iOS and Android.
Invert is a Rubix Cube-like puzzler in which you have a select amount of moves to change the grid into a single colour. By using points at the side of the grid to flip a certain pattern of tiles, the answer can be super easy...or horrendously difficult.
With 20 levels to play through and 160 unique puzzles, you've also got two mode-types: campaign and challenge. Campaign lets you take your time in carefully choosing your moves, whilst challenge puts a timer on it - for those who like the added pressure.
If you're feeling really boss, there's also an expert mode too which ramps up the difficulty to 'oh god, why?' levels. But, props to you if you live for the challenge.
Grab Invert on the App Store for £2.99/$2.99 or on Google Play for a similar price.