I've been using Cakewalk by bandlab its free and works pretty well for my needs. I also use a presonus audiobox usb as my interface. check out the links
BandLab: Make Music Online
AudioBox USB 96 | PreSonus
i saw this post trying to find a pedal for my Little Mark Vintage, turns out a Boss FS-6 in latch mode works fine with it, i would imagine it will work for your D2 as well.