# ChessLab — Play, analyze, improve > Play, analyze, improve (iPhone/iPad app by Thierry Maeder.) - Source: https://appshunter.io/ios/app/chesslab/id6793097336 (this page in markdown: same URL + `.md`) - Developer: [Thierry Maeder](https://appshunter.io/developer/1896297738) - Category: Games, Education, Board, Strategy - Price: Free - Age rating: 4+ - Requires: iOS 18.0 · 114 MB - Languages: American English, French (France) - Released: 2026-08-04 - Data updated: 2026-08-20 - User reviews in markdown: https://appshunter.io/ios/app/chesslab/id6793097336/reviews.md ## What is ChessLab? ChessLab is a complete chess companion for iPhone and iPad: play, analyze, train and experiment, with the Stockfish engine built in and without ever leaving the app. PLAY VS STOCKFISH Take on Stockfish at any strength you like, from beginner (~900 Elo) to maximum (~3190 Elo), with or without a clock. Hints, a warning before risky moves, and an evaluation bar can all be toggled on demand. TWO PLAYERS Play locally on the same device, with a "pass-and-play" mode that flips the pieces so both players read the board comfortably. ANALYZE Run a game or a position through Stockfish: move-by-move classification (inaccuracy, mistake, blunder, brilliant move…), an evaluation graph, best- move and opponent-threat arrows, and auto-play through the moves. Import by PGN, FEN, position editor, or photo scanner. OPENINGS Pick an opening and step through it move by move: every move is explained, the alternatives are offered, and colored arrows link the board to the move list. 58 hand-written openings (bilingual), with simplified spaced-repetition training to memorize them. PUZZLES Over 100,000 tactics puzzles from the Lichess database, filterable by rating and theme, plus puzzles generated automatically from your own mistakes in analysis. Spaced repetition and progress tracking included. LABORATORY Pit two Stockfish configurations against each other over a series of games to compare their strength, with an estimated Elo gap and confidence interval. EDITOR AND SCANNER Set up a position by hand, or scan it from a screenshot or a photo — review and correct the recognized position before playing or analyzing it. BUILT FOR IPAD Full-size board with move list, graph and MultiPV visible at once, keyboard and trackpad support, polished portrait and landscape layouts. iCLOUD SYNC (optional) Turn on iCloud sync in Settings so your games follow you across all your devices, via your private iCloud. No account to create, no ChessLab server. Off by default: the app works fully offline. PRIVACY Offline by default: no ChessLab server, no analytics, no ads. Your games and settings stay on your device. iCloud sync, if you enable it, uses your own private iCloud — your data is never shared with the developer. Fully bilingual, French and English. ChessLab embeds the Stockfish engine (GPLv3 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). ## Version history (last 3 releases) ### 1.3 — 2026-08-14 THE BOARD FINALLY ANSWERS YOUR FINGER Releasing a piece slightly off the intended square still plays the move, the way the major chess sites do. The target square lights up while you drag, the legal move dots follow the piece you are holding, and the piece lifts instead of hiding under your finger. Tap-to-move gets the same tolerance. Backing out stays free: releasing on the starting square cancels nothing but the gesture. FAIRER ANALYSIS The accuracy score is no longer inflated by endgame moves played in an already-won position: every move now counts for what was actually at stake. An analysis left too quickly could stay stuck on "Engine idle" with no graph and no classified moves — it now resumes on its own, right where it stopped. PLAY Controls merged into a single row. The "risky move" warning now reasons in win probability instead of a raw threshold: it speaks up when the game really turns, and stays quiet once it is decided. The clock counts from the first move. LAYOUT iPhone locked to portrait, where the board stays large. No horizontal overflow left, even at the largest text size. On iPad, a game in progress survives switching to Split View. FIXES PGN import from the web, starting position preserved on export, English translations completed, and two screens can no longer fight over the engine. ### 1.2 — 2026-08-11 OPENINGS — COMPLETELY REBUILT • A simple, guided reader: Pick an opening, then step through it move by move. Every move is explained, and playable alternatives are clearly offered. • 58 hand-written openings, bilingual (French / English) with verified main lines: covers all major openings (Ruy Lopez, Italian, Sicilian Najdorf/Dragon/Sveshnikov/Taimanov, French, Caro-Kann, King's Indian, Nimzo-Indian, Grünfeld, Queen's Gambit...) plus many systems and gambits. • Colored arrows on the board linked to the move list: green = recommended move, blue = alternatives, red = trap, orange = inaccuracy. • Simplified training: Spaced repetition runs automatically. Recall the move and tap "Continue" — your review schedule is managed automatically with no extra setup. • Alphabetically sorted list, French opening names, and progress synced via iCloud (when enabled). IPAD & MAC • Redesigned interface: A persistent sidebar (modes + tracking) with a dedicated detail area replaces the scaled-up phone layout. (iPhone keeps its tile grid). • Edge-to-edge board in "Play vs the computer" (full height in landscape, full width in portrait). Two Players and Puzzles adapt seamlessly to large screens. • Pointer & trackpad support with cursor highlighting on active squares. • Mac keyboard shortcuts for every mode. ICLOUD SYNC (OPTIONAL) • Turn it on in Settings: Your games, puzzle progress, and openings follow you across devices via your private iCloud. No account required, no third-party server. Off by default — works fully offline. ANALYZE, PUZZLES & PROGRESS • Analyze step-by-step: Walk through Stockfish's best continuation one half-move at a time. • Progress Dashboard: Track your record against the computer and your puzzle stats on the home screen, with targeted puzzle sets available in one tap for weak themes. • Scanner upgrades: Added a processing indicator, off-main-thread processing, and significantly improved piece recognition reliability. COMFORT & SETTINGS • "Play vs the computer": The opponent is now simply called "the computer" (Stockfish is still credited in Help & Licenses). • Board & piece themes: Select from 4 board styles and 3 piece sets with live previews in Settings. • Contact support: Added "Contact the developer" under Help to send feedback or report bugs directly by email. FIXES & UNDER THE HOOD • Fixed a potential crash when exiting the Analysis screen and hardened engine lifecycle management. • Stockfish recompiled from source with ARM (NEON) optimizations running off the main thread — faster analysis with zero UI stutter. • Post-game analysis is now served from cache to prevent recomputing engine evaluations on previously reviewed moves. ### 1.0.1 — 2026-08-04 No release notes. ## More apps by Thierry Maeder - [Speed Vario](https://appshunter.io/ios/app/speed-vario/id6766510876) All apps by Thierry Maeder: https://appshunter.io/developer/1896297738 --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-20.*