Pulsar Chess Engine2.50 - App Store

The Pulsar Chess Engine plays Chess and six variants all with multiple levels. The variants are Chess960, Crazyhouse, Loser's, Atomic, Three Checks and Giveaway. Rules included in-app. In addition, there is also a review mode to look at the user's log file with analysis available for non variants. 10 game collections of classic and modern master games are included to look at including Kasparov, Fischer, Carlsen, Capablanca and Morphy 1858 collections. These collections and the log file are searchable.

Pulsar values mobility and active positions. In app there is an article with more on its playing style and how to train against it. With the variants, each has its own style. Chess960, Three Checks and Crazyhouse are the more chess like variants and adoptable to learn to play for anyone with interest. The rules of all games are in app.

Pulsar has levels of play from beginner too advanced. Games with a time control are the hardest though Pulsar doesn't call the player's time. The time is more to handicap Pulsar's strength, but users will have a clock and can see if it's gone negative if they want to play the time control.

The game button - configure game menu item, lets the user control the variant and difficulty. It defaults to Chess at Easy(lowest level) but remembers the current settings when the App restarts. There are choices of pieces and board color schemes. The Pulsar program was originally developed by me for computers starting in 1998 and came to mobile for the first time in 2014.

Pulsar's board is accessible to the blind using Voice Over, a screen reader. Tap on a square and it will say whats on it and double tap to move or choose from three move methods. A screen reader can normally read anything with text like a button, but a board is a collection of images. To make it accessible, text must be returned to Voice Over when a tap is in the area of a square.

Pulsar began as a chess program and later learned variants. It ran extensively on two servers for many years both at chess and variants. The ratings on the board reflect strength I saw in rated play on handicapped bots. They are not 100% exact but generalizations I made from the various bots I ran at different settings.

If in the new game selector, Play vs. Computer is unchecked the user can move for both sides. This is to allow two people at same location to use the App as a board for a game and have the app enforce move legality and results for whatever variant is selected.

Version History Fix for broken Game menu in iOS 27 2.50 Sep 15 Fixed crazyhouse game logging where the player had black. Previously playback broke after the first drop.
Fix to highlight the last move after a castle move in chess960. 2.45 Jul 18 When viewing game collections, can now filter games by search term 2.40 Jun 30 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. 2.30 May 13 Crash Fix 2.27 10/28/2025 Added "Show Game Data" to Game menu when viewing games 2.25 09/04/2025 Fix for bug in writing promotions to log file introduced with change to more standard PGN. 2.21 08/07/2025 Writes game log for chess games in a more standardized format to be read by more outside apps if exported
Fix for when reviewing giveaway games in the log file it was sometimes ending early and not showing the complete game 2.20 08/05/2025 Fix for users current level choice increasing by one when exiting review mode by starting a game
Fix for crazyhouse pieces not being droppable from captured piece palette in review mode
added numbers 1-8 next to first eight level names
Fix for flickering in move animation in opening moves of timed games 2.15 05/11/2024 Now animates pulsar's moves with an option to turn this off in settings. 2.10 05/03/2024 Fixes for some buttons being to close to top of screen on iPhone. 2.00 10/17/2023 Added a new level after difficult 1.97 08/29/2023 Fix to flip the coordinates on chess board with new flip feature 1.96 08/27/2023 Option to flip the board on the review screen
Chess engine analysis available in chess960 1.95 08/24/2023 Added four new game collections for new installs. Existing users who delete their extra game collections will have the option to get the current ten extra game collections. 1.94 01/07/2023 Games were retract move is used will be marked unrated in the log file game listing 1.93 08/24/2021 fixed excessive redrawing bug 1.92 08/22/2021 Made the regular chess easy level a little easier. Level 2 is the old easy as that level wasn't much different and level 3 resumes as normal
fixed bug on some devices that when app first launches there was a delay on making first move
Can now make moves when reviewing log file games. 1.91 08/15/2021 Fixed some layout sizing issues introduced in last release. 1.90 05/20/2020 Support for all iPhone screen sizes 1.89 04/28/2020 bug fixes covering new updates 1.88 04/21/2020 Show book moves now on by default when looking at games from game collections and the user's log file
Added translation of "How to beat Pulsar" in German and Italian 1.87 04/18/2020 Added "How to beat Pulsar" help option on Game menu 1.86 04/15/2020 Better support for dark mode
Settings and New game view which were broken in dark mode before, fixed
Black board background option in settings
In Open log file flow, option to get additional PGN game collections 1.85 04/13/2020 German Translation 1.80 12/18/2019