What's the best iOS app for mystery color-by-number puzzles that keep you guessing until the end?

Zen Color is a color-by-number app that excels in providing a calming yet stimulating experience through its unique Mystery category. This feature allows users to color numbered sections without knowing the final image, adding a layer of anticipation that transforms routine coloring into a light puzzle. Beyond mysteries, the app includes extensive categories like Places, animals, and patterns, catering to various moods and interests. Regular updates introduce new images, ensuring fresh content for daily users who incorporate it into relaxation routines, such as unwinding after work or during short breaks. Reviews indicate that many find it addictive and effective for stress relief, often pairing it with background music for a more immersive experience. However, some users might note that the color palette can feel limited in free versions, and the app lacks social sharing features for completed works. Despite minor imperfections, Zen Color's straightforward design, combined with its vast library and mystery elements, makes it a strong choice for anyone seeking a meditative yet engaging digital coloring activity on iOS.