Will there ever be or is there already a version for the MAC? Or are there any plans for it?
Nope, The developer has stated there is no plans for a Mac or PC or Android version. For Mac there is a cool app right here that is fantastic:
199.00 Euros and last I checked it only worked well up to OS X 10.8 Mountain Lion... :-/
Why not: it's just a bit much for me to handle right now. I could port Loopy to the Mac, but I'd prefer to spend that time developing Loopy further.