OpeningTree - Chess Openings2.75 - App Store

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.

Version History Fix for broken Actions menu in iOS 27 2.75 Sep 15 When viewing game lists, can now filter games by search term 2.70 Jun 28 Fix for formatting of opening book on numbers greater than 100,000
Added two classic game collections to the existing, Botvinnik and Karpov. Users who have already installed the extra PGN/games can delete it and have the option to reinstall with the new collections. 2.60 May 13 Increased opening database by 100K newer games
"Save Board to PGN" option now writes in standard PGN format not algebraic 2.30 08/26/2025 Increased opening database by 195K newer games 2.25 08/05/2025 Added Carlsen and Morphy1858 PGN game collections to the classic games. Existing users who delete their extra games will get a chance to get PGN games again and get the new ones. 2.06 08/27/2023 New look for move list on iPhone 2.05 08/14/2022 restored the ability to change settings which broke in 2.01 2.02 06/07/2022 bug fixes 2.01 04/26/2022 Support for Dark Mode
Wood, Olive, and Marble board choices
Announce Empty setting for Voice Over users
supports all iPhone sizes 2.00 05/05/2020 German translation 1.96 01/09/2020 Translated to French 1.95 11/25/2019 complete spanish translation 1.94 11/19/2019 added Spanish localilzaton 1.93 10/01/2019 Fixed move arrows that got broken from being accessible for the blind with new graphics 1.92 05/30/2019 Forward and Backward buttons now use graphical images not text based drawing
More work on the Italian translation 1.91 05/15/2019 Updated the opening book to be built on more games including the more recent 2018 games both players rated over 2300 and some 2017 games not added yet from final part of year 1.90 04/10/2019 fix so Italian translation shows 1.86 04/07/2019 First translation build. now translating to Italian 1.85 04/05/2019 Fixed a bug where if one rook moved twice in the opening it turned off the right for the king to castle with the second rook. 1.82 03/22/2019 Made OpeningTree's promotion view accessible to the blind and visually impaired.
Fixed the speak move announcement for Voice Over users so that going forward announces the move not that they tapped the forward button. 1.81 03/16/2019 Fix for some bugs in the Voice Over touch move system for the visually impaired or blind Now responds more accurately to touches without losing track after doing several things. 1.80 03/12/2019 Board is now 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. On iPad disable drag move for best results in apps settings. If it finds drag move on on program launch, it sends an announcement recommending to turn it off for Voice Over users. 1.76 03/11/2019 A new menu item, Control Bar Menu, is added to settings. This is off by default and intended for the visually impaired using voice over. If it is on, tapping show or hide control bar will display a popup menu that also has at top show or hide control bar but also the four navigation button choices such as backward one, below it
About OpeningTree, on actions menu, second paragraph, updated to explain how the Control Bar Menu item works 1.75 03/06/2019 Updated database that gets the opening name to have more data 1.73 03/04/2019