Yep depends on how strong...are you planning a whitewater river scape? In fast flowing environments the substrate is constantly on the move so plants don't get much opportunity to find a foothold. But I'd agree Bolbitis heudelotti and Anubias spp. are well adapted to strong flow...tough leaves and roots to rock instead of substrate, and any moss that naturally clings like fissidens. You could also try Crinum natans it also has tough leaves and likes good flow, and anything with strap like leaves such as vallis or sagittaria spp. some, I think, prefer high flow too. You could give eleocharis spp. a go too.