Color by Number - Mandala Book is an iPhone application that offers a vast collection of mandala-style pictures for adults who love antistress coloring pages. The app is free to download and has an easy-to-use interface. All the pictures are conveniently divided into categories, allowing users to find their preferred mandala coloring page quickly.

The app pays attention to detail for each picture and emphasizes usability, making it very easy to use. The mandala coloring pages are incredibly beautiful to color over, and the app allows users to share their finished work on social networks. Besides, there is a special tab called "My Gallery" where all the coloring pages that users once started coloring by number are saved.

When using the app, users must follow the color palette and numbers in the picture. They only need to click with the selected color on the highlighted area, and the app does the rest. If some mandalas are difficult to color, users can use special hints or the app's fast coloring function. Color by Number - Mandala Book also offers a Premium Purchase that removes ads and provides daily replenishment of boosters, among other benefits.