NewPipe, FreeTube, LibreTube, Piped, AIMP, nuclear, SkyTube, Strawberry, MediaTube, VueTube, Kaku, Gyawun, OGYouTube, Tubex for YouTube, CherryPlayer, quietube, YouView, MotionBox, MenuTube, ProTube, VinnPlayer, Tubbler are some alternatives to SMTube.