Hosting sites compatible with MyFBG are Yahoo! Fantasy, ESPN Fantasy, NFL Fantasy, CBS Sports, MyFantasyLeague, FFPC, RT Sports, Fantrax and Fleaflicker. As of April 20, 2018 all these sites are live and league import is working between them and Footballguys.
If you use a different site, I'm afraid we won't be able to offer integration this year. That includes FanStar and NFFC, among others.