With most people now carrying portable chargers in their backpacks, phone battery conk-outs aren’t the journey-ruiners they once were. But according to the people behind the excellently-named Finger Pow, on-the-go charging could be a lot more convenient. Currently funding on Kickstarter, it’s essentially a series of tiny power banks - each no bigger than a USB drive - that you attach to the bottom of your phone when you need a quick boost. They live on a 5000mah charging bank, and each Finger Pow can charge your iPhone 8 to 25% capacity. Need more? Just swap it for the next one on the bank. They use magnetic charging, with adaptors for lightning, micro USB and USB Type-C. Back the project for $40 and you get four Finger Pows, effectively a whole charge.