The Juno Power Jumpr does what most other portable device chargers do, namely provide power when electricity is scarce, if with the addition of a further power-- jump-starting cars in times of need.
In fact the 6000mAh battery delivers a 12V output at peak 300A via dedicated port. According to Juno Power this allows it to jump-start most 4- and 6-cylinder engines. No such luck for your V8, though.
The battery includes a jumper-cable attachment, and a built-in chip prevents lithium-polymer cell reverse charging.
As for mobile devices, a separate 2A output provides via micro-USB.
The Jumpr is currently available on a pre-order basis, and should start shipping from May-June.