Features:

Modular design
Easy integration ( basic setup can be done in a few minutes )
Deep customization: Add different controller types based on platform, add theme overrides on a per widget basis, and more!
Heavily commented, and tooltips added to most exposed variables and functions!

Number of Blueprints: 19

Input: Gamepad, Keyboard, Mouse, and any other input types you want to add.

Network Replicated: No (input is always local, so it does work in multiplayer games)

Supported Development Platforms: PC, Mac, Linux

Supported Target Build Platforms: Tested on PC, but should work on all other platforms

PolyHavoc

Product types