I am a teacher that would like my Advanced Design students to make a simple 3 wheeled robot using the parts from the sparkfun 101 inventors kit. They will design and 3D print their own chassis, wheels etc. My question is, what motor controller should I buy? We are using the DAGU DG01D motors from the kit and want to use the Android App to control it. I have very little experience with these kits and want to make sure I get the correct one.