Hi Sean! Franklin Richards is friends with the Power Pack but isn't considered a member, since the main team are siblings.

As for the Future Foundation, two versions of Franklin have been of the team - his mainstream child self, and an adult version of Franklin who traveled back from the future. Despite that, the younger Franklin doesn't feel as at home with the Foundation as his sister, since - while his powers allow him to warp reality - he's not a super-genius like Valeria.