One of the hidden features that Apple built into iOS 7 is driver support for console-style game controllers, both wired and wireless. Only one or two manufacturers have stepped up to the plate to produce game controllers for iOS devices and Logitech is one of them.
Its PowerShell controller allows you to slot in an iPhone 5/5s or iPod Touch (latest gen) and hold it like a gamepad. It has a directional pad on the left, four-button array on the right, and two shoulder buttons.
What's more interesting is that the PowerShell, as the name suggests, also comes built-in with its own 1,500mAh battery - a great boon if you intend to game for extended periods on your iPhone.
The PowerShell is a longish device about the length of a PS Vita (or perhaps a little longer). It's a little long to completely fit in a pocket but if you don't mind it sticking out a little bit, it can still be considered "pocketable".
The design of the controller is such that you must use a naked iPhone 5/5s - no casing of any kind will be able to fit into the PowerShell's slot.
Slotting in an iPhone is pretty easy. You put it in bottom first, so that the Lightning port aligns with the PowerShell's and then you just push it in.
The iPhone stays in there only by friction - there are little rubber bumpers on the inner edges of the slot that keep the iPhone from falling out and also prevents it from being scratched as you insert or remove the phone.
The PowerShell has cutouts in all the right places so you have access to all the iPhone's functions. There's a cutout for the volume and mute switches, as well as the back so that you can still snap photos with the controller attached.
There's even a little round cutout for the headphone port - it's pretty deep inside, so Logitech has provided a little adaptor so that you can still plug any type of earphones into it.