My son loves the Michael Vey series by Richard Paul Evans. He reads the books and listens to the audio versions over and over again. They do not specifically discuss ADHD but the main character has Tourettes Syndrome, as well as the author who wrote the books for his son. The main character and his friends all have special powers that they use to save themselves and others, while having to overcome many challenges in their way.
Jacko Willink’s, The Way of the Warrior Kid: From Wimpy to Warrior the Navy Seal Way (there are two in this series so far) and his newest kids book, Mikie and the Dragon, are also great. Jacko is a retired Navy Seal who writes on leadership. His kids books teach kids to find their inner strength, to work hard no matter what challenges they face, and to be the best THEY (not others) can be.