Chessbook to Learn Openings
I've been using Chessbook for a few weeks. I really like the learn openings by rapid repetitions method. You can use pre-made repertoires, create your own, or you can import lichess studies. There is even a option to connect to your lichess or chess.com account. The free version is limited of course. If you try, the first thing to do is change the appearance to lichess or chess.com, otherwise the default chessboard is quite hard to look at.