THe nothinglabs in his instructable explains how to build the simplest DC motor controller. It supports PWM speed control along with direction and enables control pins. Due to its rugged hardware design, it withstands peak five amps or continuous 2.5 amps without the heatsink.
The controller is built by using a couple of TIP120 Darlington transistors, two 220 ohm resistors, and standard 12 relay. It is assembled without the need of PCB – directly on the relay itself. So if you’re looking for the fast solution, this may be a savior.