iPaint - Coloring Book is a coloring app designed for adults who want to relax while coloring in beautiful illustrations. This app offers a wide selection of all different kinds of drawings: mandalas, animals, butterflies, everyday objects, simple designs, geometric designs, and much more.
Coloring in iPaint - Coloring Book is typical for this kind of app: select a drawing from the gallery (some are premium and require payment) and then start coloring with a wide range of carefully selected palettes, so no matter what colors you use, it will still look good. You can zoom in on the drawing to see the details better, too. To add color, all you have to do is tap on the white space to fill it with color automatically.
iPaint - Coloring Book is yet another coloring app for adults on Android. While there's not much different about it, it has lovely palettes and beautiful drawings, so it's a good choice among all the available options.