I loved Pairs but it was AGA only PAL or something. I don't recall but it never made the move from my A1200 to my 4000 and I was just considering re-writing this one if I ever got time (which I never do), for DE, and hopefully AOS4. Unfortunately I can't read much German, and I'm at work and can't open the LZ archive of screenshots so I'll have to wait till I get home to take a look.
Well, it looks like it's written in C and uses stromwizard.library for UI stuff.