The best alternatives to Little Sun (Kickstarter) are ChargeKey, PLUG, and Doblet. If these 3 options don't work for you, we've listed a few more alternatives below.
Lightr Smart Charger is a tiny and portable smart charger. Lightr is combination of size and power. Lightr gives cableless solution to the old problem of charging. Its tiny silhouette makes it perfectly portable as it fits into your smallest pocket. 246% funded already! Follow the Lightr's campaign live on Indiegogo.