The premise of the Mu is simple - it's a 1 Amp mains to USB adaptor that folds to a flat profile as shown below, making it easy to slip into a bag / pocket.
How well does it work? Perfectly! It feels very well made and charges all of the devices I tried it on just fine. A 2 Amp version that will be ideal for charging tablets is coming soon according to the published 2013 product pipeline, which also shows forthcoming EU and US adapters, a power cord (nice!) and a laptop power brick.
If there's one downside to the product it could be the price... at £25 from MobileFun convenience doesn't come cheap, but for certain scenarios it might just be worth it - my better half has claimed ownership of mine as the Nexus 4 charger for her handbag.
Click here to view the item