Like the RAVPower above, this charger will detect your devices to deliver the fastest charge possible, plus it has one extra port and the free microUSB cable. It recieved 4.5/5 stars from Amazon customers.
Here are two other USB chargers we found on sale today:
Fremo 13000mAh Power Bank $16 w/code 0728UWN16(Orig. $30) | Newegg