ChessLab

ChessLab is a complete chess companion for iPhone and iPad: play, analyse, train and experiment, with Stockfish built in, without ever leaving the app.

OPPONENTS THAT PLAY LIKE HUMANS
Nine characters played by Maia-3, a network trained on millions of human games: it does not look for the best move, it plays the one a human of that level would play, blunders included. Each has a style, a repertoire and a temperament, and a level set on the human scale. Or take on Stockfish, from beginner (~900 Elo) to maximum (~3190). Optional clock, hints, a warning before risky moves and an evaluation bar, all on demand.

ANALYSE AND UNDERSTAND
Every move is graded (inaccuracy, mistake, blunder, brilliant…), each player gets an accuracy score, and the app tells you why a move was bad. The Coach adds the share of players at your level who play it. At the end, it offers to turn your mistakes and missed mates into puzzles. Load a game by PGN, FEN, position editor or photo scanner.

DAILY SESSION
Every day, what to review: opening positions that are due, missed puzzles, an endgame. A streak of days and medals to keep you going.

OPENINGS
58 hand-written openings (bilingual), checked against the engine: every move is explained, coloured arrows tie the board to the move list, and spaced repetition makes them stick. Import your own repertoires as PGN too.

ENDGAMES
78 courses proven by endgame tablebases: no move taught gives up a win, no defence offered loses a draw. Plus free training, where any move that keeps the verdict is accepted.

PUZZLES
Over 100,000 problems from the Lichess database, filtered by level and theme, plus your own, drawn from your mistakes. Personal rating and “At my level”.

VARIANTS AND MORE
Chess960 and eleven variants against the computer (King of the Hill, Three-Check, Horde, Atomic, Crazyhouse, Duck Chess, Barricades…), each with its own analysis. Two-player mode, and a Laboratory to compare two Stockfish settings.

IPHONE AND IPAD
A large board with side-by-side panels on iPad, keyboard and trackpad, portrait and landscape. Fully bilingual, French and English. Optional iCloud sync, off by default.

PRIVACY
Offline by default: no ChessLab server, no analytics, no ads. Your games stay on your device.

ChessLab embeds the Stockfish engine (GPLv3 license), the University of Toronto's Maia-3 network (AGPLv3 license) and free vector piece sets — cburnett (GPLv2+/CC BY-SA), chessnut (Apache 2.0) and merida (GPLv2+). Full source code and license notices are available from within the app (Settings → Licenses).