Linearflux LithiumCard Hypercharger

Best price: £39.99 | Capacity: 1,200mAh

While other chargers here can be transported in pockets, this diminutive unit will easily fit into a wallet or purse as it’s just five credit cards thick. There are versions for Apple Lightning and micro USB, and the cable and charging USB are cleverly built in. It works well, too, matching the quickest chargers here. It’s useful if the two plugs are all you need, although it’s pricey and capacity is small.