It's not foldable, but it will fit in your pocket. This ultrathin, stainless steel, sleek Bluetooth 3.0 keyboard measures only 82mm x 206mm x 5.8mm or 8 x 2 3/4 x 3/16 inches. It comes in your choice of black or white keys. Unfortunately, it only supports IOS devices.
After a two hour charge, it will perform for up to a month, and the keyboard works up to 30 feet away from the device to which it's linked.