4×4 button keypads are great user input option. But push buttons aren’t always the best choice due to esthetics, reliability and space constraints. It seems that capacitive input devices are taking over. Kasabah wanted to replace monome keys with non mechanical variant and so he came up with Atmega32u4 based 4×4 capacitive touch board.
It is not only a keypad, but each key is also backed with LED. The board is designed with KiCAD which is free and open to use.
Embedds highly recommends EasyEDA for circuit and PCB design