Bumpy seat: textured seat provides plenty of texture and will even let your wiggler move from side to side without falling out of his/her seat. You can buy this at your local Wal-mart, Target, or sporting good store.
Bouncy seat: Sitting on an exercise or balance ball helps your wiggler get the wiggles out. There are different type of balls. If you have a tile floor, I recommend that you invest in the balls with sand in them so the balls don't roll away. You can buy these at your local Wal-mart, Target, or sporting good store. You might also check with your gym to see if they would give you their old exercise balls.
Fidgets: Give your wigglers something to do with their hands. There are many commercially made fidgets like the long, skinny erasers. I like to make homemade ones out of a balloon and lentils. You can also put other things such as flour or sand in the balloon. Use a funnel to put the lentils in the balloon. Don't buy cheap balloons, or they will break quickly!
You'll get more ideas here: