Brain Games - Boost memory power with free brain games
Bitsbox - Monthly code projects for kids
Dualnback.works - Dual N-back is a specific brain training exercise, that's been shown by research - it might improve fluid intelligence.
Kano - The educational computer and coding kit for all ages
Pixelogic - Daily Picross - Nonogram logic game with 5000+ puzzles and a daily puzzle
Robo Wunderkind - Coding and robotics made easy for kids 🤖