This puzzle game is all about creating new objects by mixing elements. You start off with the four classical elements (earth; fire; water; air), but before long you're figuring out how to fashion everything from household boilers to dinosaurs.
Some of the combinations are fanciful to say the least, and it can be a tad frustrating when you can’t find anything new. But it’s always rewarding when you do. Note that there’s progress sync when signed in, so do sync before you go offline, unless you want to start from scratch.
Battery munch: less than five per cent per hour. But then this is essentially an offline web app.
Podcasts! When you’re up in the air, they're the perfect way to avoid listening to the rabble around you. And Pocket Casts is the best premium player around, with a great range of features whether you’re looking for new things to listen to, or wanting to improve a talky show by speeding it up, trimming silences and boosting its volume.
Because it’s so easy on the battery and plays in the background, Pocket Casts also works nicely with some of the other apps in this list, such as Instapaper and Little Alchemy.
Battery munch: a few per cent per hour, especially if you use it with the screen off.
One of the finest mobile puzzle games in existence, Threes! has you swipe numbered tiles around a grid, aiming to merge them and make new tiles with higher numbers. The way the game’s designed cleverly forces you to think several moves ahead, and it becomes increasingly claustrophobic as your room for manoeuvre reduces.
There is a free version of the game, but you’ll need to ‘charge up’ how many goes you have by watching ads. Frankly, just spend a few quid on the paid version, and settle down for hours of Tetris-style obsession.
Battery munch: pretty much ten per cent per hour on the dot if the game’s ‘conserve battery’ option is on.
This entry plonks you in a spaceship hurtling towards the centre of the galaxy, using a drive mechanism built by aliens who’ve mysteriously vanished. You periodically stop along the way to trade, mount expeditions, and recruit crew.
It’s all algorithmically generated and text-based, and so comes across like someone glued space-trading classic Elite to a Choose Your Own Adventure book. And, although it can get repetitive, it’s amusing to blaze through a virtual galaxy when soaring through the air in a tin can with wings.
Battery munch: about 12 per cent per hour.