If you're near a outlet, you can plug a microSD plug into POP, and use the power bank to run your phone. At the same time, you can charge up your Galaxy S II batteries to have them ready for your next outing.
The product is being crowd-funded on Indiegogo, and 203 backers have raised $2485. That adds up to 12% of the $20,000 that the company is seeking. There is one month remaining on the Indiegogo listing, and the product is expected to ship in September. For those seeking to get in early, POP costs $15 without the battery, $22 with an 1800mAh juicer. The regular retail price of the power bank with the cell will be $55, and there are other various offers that you can find at the sourcelink.
Regular power banks have to be held in your hand, or shoved in your pocket with a cord hanging out. With POP attached to the rear of your handset, this isn't necessary. And unlike other power banks, the amount of power you have is limited only by the number of freshly charged Galaxy S II batteries you can carry.