At the moment, Willo is intended for use by children ages 6-17. We're focusing on those who tend to have the most difficulty brushing, and our goal is to emphasize the importance of creating great brushing habits from an early age (healthy mouths for healthy futures! :))
Although Willo currently isn't optimised for those 18 and older (check our article about Willo and adults), we're working on ways to make Willo more helpful for adults in the near future—so please stay tuned!