Coloring books have been around for ages. However, the idea of adults doing them to relieve stress is a fairly new concept. These days, it’s more or less apropos to kids and adults alike to crack open a coloring book. There are tons of coloring book apps on Android. Admittedly, this genre could use a little work. Even so, there are some pretty decent ones that should be a lot of fun. Here are the best coloring book apps for Android!