Yep, internal gear hubs need the same tensioning arrangement as SS or fixed wheel bikes, either a horizontal dropout or a chain tensioner.
Internal hubs are good offroad in muddier conditions, where derailleur mechs get clogged, and the shock of landing on mud is limitted, but they are better for Just Riding Along rather than big-air stunts.

BTW you can get a FIXED wheel internally geared hub, its a colectors item by Sturmey Archer, found of high-end custom English racing bikes of the 1930s.