What's a good Android app for relaxed coloring by numbers without aggressive monetization?

Pure Color by Number Book is positioned as a direct alternative for users seeking a simple, stress-free digital coloring experience. Its primary strength lies in an uncluttered interface where users tap numbered segments to fill them with a corresponding color, creating detailed images piece by piece. The app offers a substantial library of pictures across standard categories like animals, landscapes, and mandalas. A notable feature is the customizable settings, allowing users to adjust the fill animation speed or turn it off entirely, though some reviews indicate the 'off' setting can behave inconsistently, requiring a screen refresh for the color to appear. For the described use case, the app avoids the pressure of timers, competitive leaderboards, or energy systems. It monetizes primarily through optional ads that can be removed and offers additional picture packs via one-time purchases, avoiding the need for constant microtransactions. However, a significant point for potential users to consider is the inclusion of religious-themed images, particularly related to Jesus, within the general library. This content is not segregated, which some users find undesirable in a non-specialized app. Despite this, for those prioritizing a calm, methodical coloring session with control over visual effects, it serves its purpose effectively. The 4.8-star rating generally reflects satisfaction with its core function as a Zen-like activity.