Sony is getting into the controller customization game late into the PS4's lifespan. The company has unveiled a DualShock 4 Back Button Attachment that, as the name implies, lets you map two of the gamepad's buttons to easier-to-reach locations on the back. If you'd rather not lift your fingers to reload or perform a special attack, you don't have to. You can specify up to three different profiles, and an OLED screen on the back illustrates your current button setup.
Source: PlayStation Blog