After my experience in the US, with A: iPhone dying after taking consecutive photos, infuriatingly quickly in cold weather, and B: charging multiple devices on very cheap chargers, I decided it would be worth investigating a few quirky, useful, but wholly inexpensive solutions.
A really innovative patented little device is the Twist + from www.oneadaptr.com . One twist and it will adapt to all world sockets. It’ll take up to 4 USB devices including an iPad. It might be quite a good thing to fidget with when bored as well. 
A slim and sleek portable charger was my choice but then there are lots of those to choose from. And I have another iPhone in here that is a duplication of my own phone. I saw so many backpackers who had lost or broken their phone. This way, I will be able to restore from iTunes and not lose all my money apps, maps and 
contacts etc.
A cool bit of kit to go in the bag is this really small but well made set of lenses for my iPhone camera
One Woman, Three Bags 