I don’t have a Eurorack so an FH-2 isn’t for me, but as I do have an MS-20 Mini, Werkstatt with CV expander and Koma Elektronik Field Kit FX (as well as a few other CV-enabled items) I picked up this recently to handle MIDI to CV tasks:
http://midimuso.co.uk/index.php/product/cv-12-octex/
My initial thought was to build a 4 voice polyphonic Moog with it out of Werkstatts, but I’ve not actually even got around to grabbing a PSU for it yet… (one day there will be time for all these experiments).
iOS allows me to experience some of the more unusual and advanced MIDI sequencing operations that aren’t open to me without investing a chunk of money into Eurorack so interfacing my iPad with hardware is definitely something I want to do a lot more of.
On a side note: I have my old 3rd generation iPad setup as a sound module for Ableton these days and it’s absolutely fantastic. A total breeze to set up - I just took the MIDI out from my Ableton interface into the MIDI in on the ioDock my old iPad lives in and some of the apps even automatically mapped the rotary encoders from my Komplete Kontrol S25 keyboard!