I haave.....nope..they arnet good for the community.....for to reasons.
If your talking about heterandia formosa, the pgmy livebearer....they may be eaten.
If you mean gambusia affinis or holbrooki thne they are quite aggresive, like tiger barbs.
Look after htme like other livebearers, just crush tyhe food ot small size for hte pgmyies.