There's only GPU apps for a couple of Sieve Projects at PG at present (PPS and Cullen/Woodall. CUDA for both, but AMD only works on PPS Sieve at present.
I did see a brief comment somewhere a while back about the possiblity of someone winding up a LLR GPU app, not sure which Project - I think PPS LLR - but nothing heard since. Given the effort and time it takes to do it however, the latter is not surprising, and if its still intended probably be a while yet.
EDIT: oppps .... cross posted there, sorry. See above re my last para which is obviously out of date ..... is that PRPNet Cuda app up and running now??