Controller option for D3

So I know that a controller is a bad idea for d3 on the sense of not being able to target a certain target but I cant help but think the good idea is mobility. I remember seeing a program that worked with D2 for use of a controller but can't remember what the program was called. If someone knows what the program is and if they have tried it and if it was any good (at least for a download to test it out) please give a shout out.