Coloring Book: Color by Number by Candy Mobile positions itself as a digital relaxation tool that simplifies the coloring process through a numbered painting system. The Android application transforms complex artwork into manageable sections, making artistic expression accessible to users regardless of artistic skill level. This approach distinguishes it from traditional coloring apps by providing clear guidance throughout the creative process. The core functionality revolves around numbered templates where each section corresponds to a specific color. The application offers extensive categorization of images, ranging from animals and nature to intricate patterns, with regular content updates maintaining user engagement. The color palette system provides pre-selected harmonious color schemes while allowing customization for experienced users. Performance metrics indicate smooth rendering and responsive touch controls, though some users report occasional ad-related interruptions during image loading sequences. User interface design employs intuitive navigation with clearly marked categories and a streamlined coloring workspace. The application maintains visual consistency through vibrant color presentation and clean line work. Real-world usage patterns show peak engagement during evening hours, suggesting effectiveness as a wind-down activity. The zoom functionality enables detailed work on complex sections, while the completion tracking system provides satisfaction through visual progress indicators. User feedback trends highlight appreciation for the diverse image catalog and stress-relief benefits, though advertising frequency emerges as a common concern. Angela Irvin's July 2025 review notes significant improvements in content curation, specifically mentioning the removal of unsettling imagery. Eden Donkor's June 2025 review praises the vibrant color presentation and calming effect, while Amy Johnston's review from the same period cites technical issues with advertisement loading that sometimes requires application restart. The application demonstrates strength in accessibility and content variety but faces challenges with advertisement implementation. The structured coloring approach successfully lowers barriers to creative expression, making it particularly valuable for users seeking meditative activities. However, the free version's advertising model may disrupt the relaxation experience for some users, suggesting potential value in the rumored premium version mentioned in user reviews.