What's a good iOS game for relaxing yet challenging puzzle gameplay?

Teeny Tiny Trains is an excellent option for those seeking a relaxing yet challenging puzzle game on iOS. The game's core mechanic is easy to grasp, but as you progress through the levels, the puzzles become increasingly complex and require strategic thinking. This balance of simplicity and challenge makes it perfect for both casual players and those who enjoy a good mental workout. The game offers a unique blend of puzzle-solving and train management, where you must efficiently route trains to their destinations while managing resources and overcoming obstacles. With its charming art style and intuitive interface, Teeny Tiny Trains provides a delightful and engaging gaming experience that will keep you hooked for hours. The availability of add-on packs further extends the gameplay, offering even more levels and challenges to conquer. It is developed by Short Circuit Studio and has a rating of 4.625/5.