Chessbook - Master openings

Chessbook is exactly what I had been looking for. It has allowed me to build a repertoire, both for White and for Black, and annotate moves as I go. It shows me exactly where the gaps in my repertoire are, and suggests moves along the way. Then it allows me to practise against any part of my chosen repertoire, varying the response very slightly each time I play, until it becomes second nature to me. It also encourages me to investigate how I would respond to novel gambit lines. This is a fantastic tool to have if you are serious about improving your opening preparedness, it is also great fun to use. And it enables a chess player to organise his openings in a way that very few competitors do - if any. One slight criticism is that there does not seem to be a dedicated support line (although there is a way to provide feedback).

As soon as I found out about this app/website (yes there is a website version) I immediately downloaded it. There is a limit on how many moves you can save on the free version, but the price for the paid for version is cheaper than a Starbucks meal and is absolutely worth it. It has other amazing features such as pre-built repertoires by titled players for potential gaps in your opening knowledge. And the discord server/community behind this app is amazing and supportive. If you are going to spend money on learning chess, this is absolutely a must

Easy to use and very clean, and this was the first app where I didn't even hesitate to by a subscription, fixed my repertoire and gained 300 elo just because I started understanding openings much better Also few features that I never met before like games of GM choose based on my repertoire with guessing their moves is incredible

It really helps me learn chess and learn mistakes and recommend to other players

App completely stopped working after a few days of subscribing to premium for around £50/year and is still crashed. Cannot contact developers because when you click on the link to contact the developers it tries to open the app which doesn’t want to open.

Used the website before and then saw there’s an app so couldn’t wait to download. I practise almost every day and it’s really improved my chess!