Download of ChessKingLearn 4.0 for Mac was on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. This free Mac app was originally created by Chess King. Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe. ChessKingLearn for Mac is categorized as Education Tools.
From the developer:
Chess King Learn is a chess teaching app. The application includes courses in tactics, strategy, openings, middle game, and endgame, split by levels from beginners to experienced players, and even professional players. With the help of this utility, you can improve your chess knowledge, learn new tactical tricks and combinations, and consolidate the acquired knowledge into practice.
You may want to check out more software for Mac, such as Master Key, Aquallegro or KeyStrokes, which might be similar to ChessKingLearn.