I recently released Sudoku Fun4Kids, a Sudoku and logic game designed specifically for young children. Traditional 9×9 Sudoku can be too complex for beginners, so I reduced the concept to 4×4 and 6×6 boards and added three different ways to play: 😀 Emojis 123 Numbers ABC Letters The goal is to preserve the basic logic of Sudoku while making it approachable for children who may not yet be comfortable with traditional number puzzles. Gameplay Here is a short gameplay video showing the different modes and board sizes: Designing for young children The biggest challenge was not the Sudoku logic itself, but the interface. I wanted children to be able to use the app as independently as possible, so I focused on: large touch targets a reduced interface clear visual feedback simple controls a hint function when a child gets stuck layouts that work across different screen sizes Making an interface simpler for young users often required more work rather than less. One Flutter codebase, three platforms Sudoku Fun4Kids is built with Flutter and is available for: Android iPhone and iPad Windows Using Flutter made it possible to keep the interaction and visual design consistent across all three platforms. For the iOS release workflow, I use GitHub and Codemagic for automated builds. Privacy by design I also wanted Sudoku Fun4Kids to follow a very simple product philosophy: completely free no ads no in-app purchases no tracking no data collection no user account required fully usable offline The Android version has also received the Teacher Approved designation on Google Play. Try it Screenshots and links to the Android, iOS/iPadOS and Windows versions are available here: https://hpwsoft.com/sudoku_kids.html I'd be interested to hear how other developers approach UI and interaction design for very young users, especially when trying to make an app simple without removing too much functionality.