There are tons:
Various hairbrushes (a new paddle brush with rounded tips is an easy to find go-to for feet. Some people find these painful instead of ticklish so be gentle using them)
Pursonic flosser attachment is pretty standard and works great for most spots
Toothbrushes (new)
Feathers
Pipecleaners
Scalp massagers
Banjo pick
Grooming gloves
Really anything that has bristles or vibrates can be used somewhere