I Can't Stop! A Story about Tourette Syndrome, by Holly L. Niner, is a picture book about tics (and TS, obviously) for kids. The kids portrayed in the book are in elementary school, and I'd say the text is good for grades 2-5, and easily read to kids somewhat younger.
It describes what tics are, and shows how Nathan (the protagonist) deals with some common ones. It also relates how tics can be easily misdiagnosed as habits or allergies (as with a constant sniffing tic), and talks about how tics can only sometimes be temporarily suppressed, and how to talk to other people about them. All of this is good, and important, and the note to parents and teachers in the front of the book also includes clearly written, useful information and a link to the TSA (Tourette Syndrome Association). The illustrations by Meryl Treatner are engaging and interesting.
But I have some reservations about recommending this book to my 10 year old with TS, who also deals with OCD and ADHD. First all, Nathan only deals with tics - he is popular, does well in school, has no problems with social interactions (except for a few that crop up with some of the tics), and he is athletic and does well in several sports. His best friend is understanding and his parents and teacher find ways to help him. Everyone is supportive and matter-of-fact when dealing with Nathan's Tourette's Syndrome.
I would have welcomed a little more realism - maybe a grandparent who huffs "I don't believe in this stuff. In my day, we just stopped when we were told or got a spanking!". Maybe a teacher who gets annoyed, or a sibling that is embarrassed (like the wonderful protagonist in Rules, by Cynthia Lord).
Nathan seems to have a pretty perfect life, except for those tics, and this made him a bit bland. And I worry that my son will think that it's ok to have Tourette's, as long as everything else is really, really good. And it's true - as long as you don't have to hear yourself blink a certain number of times before you can finish a math problem, as long as you have a such a great and supportive best friend, and as long as you win soccer tournaments, having tics doesn't have to be such a big deal.
As with many disabilities, in the world of TS there seem to be some big divides between people with different degrees of severity, and/or different types of problems that are often associated with TS. This book would probably be fine - good even, if a bit pedestrian - for kids dealing with "TS only" (as Nathan does), but it's not great for TS Plus (TS+ includes OCD and ADHD, which many agree can be more challenging than tics). I guess I'm still waiting for a good kids' book on that. Maybe someone at Life's a Twitch! could write one?
While I'm at it, here's a useful post "minimizing confusion" about TS. If I were to write a children's book on Tourette's Syndrome, I would include this site (along with many of the others given above).