We might bang on about switching off our brains, but really we're all addicted to a mental challenge. Here are 10 of the most mind-testing apps for iPhone and Android...
Droplitz Delight iPhone, £1.79/Android, $1.97
Spin the connection tubes to allow the smiley-faced water droplets to fall unhindered into the bowels of the earth. Trickier to do under pressure than you might think.
Unblock Lego Android £free
Slide the onscreen Lego bricks around to release the red block. Looks like it should be easy, but by jove it can get tricky. In relax mode you have all the time in the world, while challenge mode encourages you to complete the puzzle in the fewest moves possible.
Mazespace of the Vor iPhone, £free
The premise sounds silly – a maze game without walls – but it's actually a very simple concept. You need to guide your space craft to a target area, but the only way you can turn is by heading in a straight line between a selection of "vortexes" (or vortices to those of us who speak English), and jumping through wormholes. Addictive nonsense.
Beat the Chimp Android, £free
Despite the innuendo-laden name, this one's actually pretty good. A test of reactions and memory, it invites you to play a game once used by scientists to test chimps. Tap the numbers in order (they disappear very quickly), pit your wits against other online players, and of course that damned dirty ape.
Trains iPhone, 59p
Flight Control dons its anorak… and you’ve moved from the air traffic control tower to the signal booth. Dull? Not a bit – frantically jab at junctions to get the right colour trains to the right colour depot then safely off the screen. If Virgin Trains can manage, eh?
MiniZoo Android, $1.99
A sweet Android re-imagining of Bejeweled – featuring a dog, monkeys, chickens… Swap positions of two adjacent animals to make strings of three or more of the same type. It's pretty ace, even if the bijou icons require rather small fingers.
Labyrinth iPhone, £1.79
Remember real-world Labyrinth? If so, this app will take you back with its spot-on graphics and realistic sound effects that roll, knock and drop in the plywood box. If not, you’re about to discover where everyone else’s childhood went in this infuriatingly addictive skill test. Finished? Labyrinth 2 is £2.99 and adds even more physics-bending challenges.
Sudoku Camera Android, €0.99
Ripping the sudoku page out of the free paper on the train is so 2009. Use Sudoku Camera to take a snap of it and play it on your phone instead. It can even solve it for you with a single button press, which does sort of take the fun out of it…
Park In iPhone, 59p
Play harbour master and direct the correct coloured boats to their respective moorings. Trickier than it sounds, thanks to the boats only travelling in certain directions. Damn those unsteerable boats.
Brain Trainer iPhone, £free
Unless you design spacecraft or spend your days wrist deep in brains, you’re unlikely to challenge your grey matter much. Brain Trainer by Luminosity.com isn’t a patch on the popular DS series, but its fun, challenging and might just stop the rot.