Did you ever find an app gerbil86? There use to be one on a website that had chinchilla in the url - that one was awesome (as it had little pictures) then there was a beta one on an excel spreadsheet style set up - which I always used into eternity for my predictions until it finally all sunk in and I could do it in my own head. I haven't really looked for one since - so can't recommend any currently set up with all the new gene combos. I think the last one included 'd' at least - but it didn't have Rex and all the spotting combos - it was just colours only.
The excel one was very simple programming - so I am sure it could be recreated with someone with a bit of know how as at least a starting point. Anyone on here with some app insights - and I could help fill in the genetic side?