Chess Openings Trainer is an iPhone application developed by Piero Toffanin. This free app is designed to make learning and practicing chess openings intuitive and simple. With a database of over 3,000 openings and 500 descriptions, this app provides a comprehensive resource for chess enthusiasts.

The interface of Chess Openings Trainer is user-friendly, with no side panels or complicated statistics to distract from the learning experience. The app displays the strongest replies to well-known variations, allowing users to confidently play the Sicilian Defense or the King's Gambit.

One of the standout features of Chess Openings Trainer is the ability to explore openings directly from the chess board. This hands-on approach enhances the learning process and helps users develop a deeper understanding of each opening. Additionally, the app offers the option to practice openings against a tireless AI opponent.

Chess Openings Trainer has been developed with the help of Stockfish, the strongest chess engine in the world. Every move in the app has been evaluated by Stockfish, ensuring accurate and reliable analysis.

For those who wish to support the developer's work, there is an option to purchase the Pro version within the app's settings. This one-time, lifetime purchase provides additional features and enhancements.

Overall, Chess Openings Trainer is an excellent tool for chess players of all levels who want to improve their opening repertoire and gain confidence in their gameplay.