Chess Aid is a free Chrome extension developed by ChessAid. Designed for learning purposes, this extension aims to help users improve their game of chess. However, it is important to note that it should not be used in live chess games.

The extension supports the popular chess website, lichess.org. To use the free trial, users must have sync turned on for their Google account. The extension offers various features to enhance the learning experience. It can highlight the best move using Stockfish, show the evaluation bar, and provide an openings explorer. Additionally, it can highlight enemy and friendly pieces under attack, as well as squares controlled by the enemy.

Chess Aid also offers the option to change the engine depth, calculate moves extra fast with bullet mode, and even play in human mode where Stockfish makes mistakes like a human. For a different challenge, users can try the hand and brain mode, where Stockfish suggests the piece to move, but not where to.

To activate the extension, users simply need to start a chess game and click on the Chess Aid extension to launch the pop-up menu. From there, they can start and stop highlighting squares, adjust the settings, and enjoy the enhanced chess experience.

Overall, Chess Aid provides a range of features to help users improve their chess skills. Whether it's improving board vision, learning openings, or enhancing tactical awareness, this extension offers a valuable learning tool for chess enthusiasts.

Please note that any feedback or issues can be addressed by joining the Discord server provided by the developer.