A free app for Android, by Next Tech Games Studios – Paint by Numbers Books.

The 3D Poly Art – Color by Number is the best free and relaxing color by number game for adult users. You can paint and color any pictures, and if you’re an artist or love to draw, it’s time to unleash your imagination. You will be able to create amazing artworks and enjoy the beautiful images that will be available in this awesome app. 

In order to play, you need to select a picture from the gallery and then select the number from the pattern that is displayed. You will find a variety of pictures, such as landscapes, animals, people, artworks, etc. You can choose to color an entire page or just a small part of the page. You can also rotate the page to get a different perspective of the picture.