Listudy is a free training platform that applies spaced repetition to several areas of chess study. Its opening trainer lets you import a PGN repertoire and drills you on it using a scheduling algorithm that surfaces forgotten lines at the right time. It also includes a blindfold tactics trainer where you solve puzzles without seeing the board, building visualization skills.

Additional modules cover endgame practice and coordinate training. The blindfold section in particular sets Listudy apart from most tactics sites — it is one of the few web tools specifically designed to train calculation and board visualization without visual aids.

All features are free and no account is required for most functions. Listudy is a good supplementary training tool for players who want to improve visualization or train openings with spaced repetition outside of larger commercial platforms.