OpeningTree vs Chess Opening Blunders
Price, ratings, monetisation and update history for both games, side by side — with what reviewers say about each.
OpeningTree
Explore chess openings with an extensive opening book and engine analysis. Analyze your games, create custom lines, and study moves from high-rated players. Accessible for visually impaired users.
- Extensive opening book
- Crafty engine analysis
- Load and analyze PGN games
- Create custom move lines
- Accessible for visually impaired
- Mark moves with colors
- Save board to PGN
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OpeningTree is a chess openings book based on high rated over the board games that lets one explore the tree of openings and engine analysis is available. Chess game files can be shared with the app to check against the book or to just view. Users can make their own side line moves and back up to return to main line. Also includes ten classic game collections and users can import their own games into the app. Game list are also searchable by tags. The updated opening book is compiled from 640,000 high rated games from recent years with both players rated 2300 and over. Just touch moves in the list or make moves on the board to see what the response is. The numbers next to moves indicate how many games resulted in wins-draws-losses. The idea comes from computer opening books as if we can open up the book and see what those moves are that people play in response to opening positions. Users do not pick an opening to study but start with the full tree. The analyze button on bottom right of board is to flip between viewing the openings move table or seeing Crafty engine analysis. +1.00 score means white is ahead a pawn. -1.00 score means black is ahead a pawn. There is a move now button to make the engine play the current best move if the users wants to try playing a position out against the engine. OpeningTree's board is accessible to the blind and visually impaired using Voice Over. With Voice Over enabled in device settings, tap on a square for info, double tap to select. Or choose from three move methods. When going forward in a loaded PGN game, moves will be announced on each tap of the forward button. Moves can be marked with colors(red, green, yellow) and colorizing a move at the end of a line will extend the line i.e. add move so it shows later. There is also an option to make a note on a position using the control bar. In the Actions menu if the user has imported a chess games file to the App, for example by opening a PGN file with OpeningTree from a mail attachment or download(long touch on the attachment/download for this option), a game from a PGN file can be loaded and checked against the book. If a user makes a new move, back up to the main line to return to the game. To ensure speed, it will only read/load a max of 5000 games. With bigger files users will only see first 5000 games. There is a Save Board to PGN option on the Actions menu. It saves the current moves to openings-user-games.pgn, a file OpeningTree will create on first save. Games are saved with opening name as white and black name to spot the lines in each game. This allows the users to export data out of the App such as favorite lines with the mail games option when looking at a game list. The App comes with six PGN game files that can be optionally installed when no PGN files have yet been opened by the App or the user has deleted their PGN files previously opened and likewise has none to access. If this is the case, this option shows when going to Actions -> load PGN. The files contain a mix of famous classical games, collections of former world champions Gary Kasparov and Magnus Carlsen's games and more recent games from two top ranked international tournaments. PGN stands for portable game notation. It's a file extension that can be used with text files that contain chess games in the PGN format. PGN files can be read by apps to display the games in them. If a game is loaded in the App one can then go to 'Actions -> show game data' to view the raw PGN text.
Chess Opening Blunders
Learn chess by studying common opening mistakes and traps. This app offers interactive lessons with over 1,250 exercises across more than 40 openings, acting as a personal coach to guide you through challenges.
- Learn opening mistakes and traps
- Over 1,250 instructive exercises
- Covers more than 40 chess openings
- Interactive lessons with hints and explanations
- Play positions against the computer
- Monitors player rating (ELO)
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Encyclopedia of Opening Blunders – learn to play chess by learning the opening mistakes and traps that have been discovered over time. The program is designed for studying the blunders in more than 40 openings and contains over 1,250 instructive exercises of varying difficulty from practical games. This course is in the series Chess King Learn (https://learn.chessking.com/), which is an unprecedented chess teaching method. In the series are included 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 course, you can improve your chess knowledge, learn new tactical tricks and combinations, and consolidate the acquired knowledge into practice. The program acts as a coach who gives tasks to solve and helps to solve them if you get stuck. It will give you hints, explanations and show you even striking refutation of the mistakes you might make. Advantages of the program: • High quality examples, all double-checked for correctness • You need to enter all key moves, required by the teacher • Different levels of complexity of the tasks • Various goals, which need to be reached in the problems • The program gives hint if an error is made • For typical mistaken moves, the refutation is shown • You can play out any position of the tasks against the computer • Interactive theoretical lessons • Structured table of contents • The program monitors the change in the rating (ELO) of the player during the learning process • Test mode with flexible settings • Possibility to bookmark favorite exercises • The application is adapted to the bigger screen of a tablet • The application does not require an internet connection The course includes a free part, in which you can test the program. Lessons offered in the free version is fully functional. They allow you to test the application in real world conditions before releasing the following topics: 1. Rare variations 1.1. 1.g3, 1.b4, .. 1.2. 1.b3 1.3. 1.d4 1.4. 1.d4 Nf6 1.5. 1.d4 Nf6 2.Nf3 2. Alekhine's defense 3. Benoni defense 4. Bird's opening 5. Bishop's opening 6. Blumenfeld counter-gambit 7. Bogo-indian defense 8. Budapest gambit 9. Caro-Kann 10. Catalan system 11. Center gambit 12. Dutch defense 12.1. Dutch defense 12.2. Iljin Genevsky system 12.3. Leningrad system 12.4. Staunton gambit 12.5. Stonewall variation 13. English opening 14. Evans gambit 15. Four knights' game 16. French defense 16.1. French defense 16.2. Classical variation 16.3. Tarrasch variation 16.4. Winawer variation 17. Grünfeld defense 18. Italian game & Hungarian defense 19. King's gambit 20. King's indian defense 20.1. King's indian defense 20.2. Classical variation 20.3. Fianchetto variation 20.4. Four pawns' attack 20.5. Saemisch variation 21. Latvian gambit 22. Nimzo-indian defense 22.1. Nimzo-indian defense 22.2. Leningrad variation 22.3. Rubinstein variation 22.4. Saemisch variation 23. Nimzowitsch defense 24. Old indian defense 25. Philidor's defense 26. Pirc-Robatsch defense 27. Queen's gambit 27.1. Queen's gambit 27.2. Queen's gambit accepted 27.3. Albin counter-gambit 27.4. Cambridge-Springs variation 27.5. Exchange variation 27.6. Orthodox defense 27.7. Lasker defense 27.8. Tartakower defense 27.9. Ragozin system 27.10. Semi-Slav defense 27.11. Semi-Tarrasch defense 27.12. Slav defense 27.13. Tarrasch defense 27.14. variation with 5.Bf4 28. Queen's indian defense 29. Queen's pawn game 30. Reti opening 31. Petroff's defense 32. Ruy Lopez 32.1. Ruy Lopez 32.2. Berlin defense 32.3. Bird's defense 32.4. Breyer variation 32.5. Chigorin defense 32.6. Classical defense 32.7. Exchange variation 32.8. Marshall attack 32.9. Steinitz defense deferred 32.10. Steinitz defense 33. Scandinavian defense 34. Scotch gambit & Ponziani's opening 35. Scotch game 36. Sicilian defense 37. Three knights' game 38. Two knights' defense 39. Vienna game 40. Volga-Benko gambit
Screenshots
Verdict
The clearest difference is price: Chess Opening Blunders at Free against OpeningTree's $0.99. Chess Opening Blunders also leads on rating (4.7 vs 4.4) and ratings volume (246 vs 31). OpeningTree's advantage is in-app purchases (none vs 1) and chart position (#198 vs unranked). On review sentiment, update cadence, ads and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Chess Opening Blunders is free to download; OpeningTree costs $0.99 up front. Chess Opening Blunders sells 1 one-off in-app purchase. OpeningTree asks for nothing beyond the download.
Chess Opening Blunders holds the better App Store score, 4.7 against 4.4. That said, the two scores are not equally well evidenced: Chess Opening Blunders has 246 ratings behind it against 31, so its average is the more settled of the two. Written reviews point the same way: 83% of OpeningTree's written reviews are positive against 84% of Chess Opening Blunders's.
Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on September 27, 2026 and September 28, 2026 respectively.
| Parameter | OpeningTree | Chess Opening Blunders |
|---|---|---|
| Price | $0.99 | Free — better |
| Rating | 4.4 (31 ratings) | 4.7 (246 ratings) — better |
| Positive reviews | 82.6% of reviews | 84.1% of reviews — better |
| Number of ratings | 31 | 246 — better |
| Update frequency | Every 2 months | Every 2 months |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Paid | Free with in-app purchases — better |
| Best chart rank | #198 — better | — |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.6 | 8.0 — better |
| Further details — not scored | ||
| Size | 52 MB | 43 MB |
| Age rating | 4+ | 4+ |
| Developer | Michael Adams | Chess King |
Customer experience
OpeningTree
Chess Opening Blunders
In-app purchases
OpeningTree
No in-app purchases
Chess Opening Blunders
- Full course$12.99
Questions
Is OpeningTree free?
Is Chess Opening Blunders free?
Which has better reviews, OpeningTree or Chess Opening Blunders?
Do OpeningTree or Chess Opening Blunders have ads?
Which is updated more often, OpeningTree or Chess Opening Blunders?
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