Maybe skipping rope, also, then! (keeping it low-tech.)
I must be in the minority, because I've tried rebounding and disliked it a great deal. Just couldn't stand the feeling. It's so rigid-feeling. Jarring. Now maybe on a big one--a trampoline. But the rebounder is so small and tight. Then there is the leg-shaker--forget the name; I think it does the same thing, with shaking up the lymphatic system, but you lie down while you rest your ankles in it. It looks relaxing. Apparently, people get a real workout, AND tend to fall asleep.