Ah, the great outdoors – a place to lose yourself, and then realise how pathetically reliant you are on mobile signals. But don't worry, you won't have to befriend a pack of macaques just yet. That's because you were sensible and bought the Sonnet, an off-grid hexagon that connects to your phone and gives it the ability to send messages or read maps without any cellular or satellite signals. Like a walkie-talkie for your phone, it has global offline maps, a panic button for sending an SOS signal, and a 4000mAh battery for topping your phone's dangerously low charge. Just don't leave it tantalisingly out of reach before getting your arm trapped under a rock.