you can use whatever slicer you want really. many use slic3r and pronterface. i have an m2 myself and i use the creator software from simplify3d. that is the one makergear recommends. if you dont mind paying for it, it is a fantastic app. you dont need 2 separate programs. its all in one, work great and its constantly being improved on. v2.0 was recently released and it came with alot of cool new features.