Chesspy
A daily logic puzzle: place rooks, bishops and knights so every numbered square is attacked by exactly that many pieces. The solo developer says the code was almost all written by Claude Code.
Official site aewnlo.github.io, verified Nov 3, 2026. Linked as “Play in browser” on the developer's studio site 037.works, which Apple's data gives as the app's seller website.
Where to play
Every platform this game is on. Links are checked against official sources; we never host or mirror games.
- View on the App StoreApp StoreReleasedFree-to-Play
Install from Apple's App Store on an iPhone or iPad.
Mobile · Official link verified Nov 3, 2026.
- Play free — official siteBrowserReleasedFree-to-Play
Runs in a desktop or mobile browser. No download.
Browser (no download) · Mobile · Official link verified Nov 3, 2026.
About Chesspy
Chesspy is a daily logic puzzle for iPhone, also playable in the browser. Numbered squares are targets: you place chess pieces, called agents, so that each target is attacked by exactly its number, and a 0 is a safe square that nothing may attack. Rooks attack along rows and columns and bishops along diagonals, all the way to the edge and through other pieces; knights join from the tenth board. Every board has exactly one solution that can be reached by logic alone, and the developer says boards whose last step can only be found by elimination are thrown out. Today's Mission is 20 boards in a row, growing from 3×3 to 6×6, with three hearts: a placement that newly turns a number red costs one. Everyone gets the same boards each day, generated on the phone from the date as a seed, and the only server is a small function that returns your Top % from anonymous scores. Sundays bring a harder mission that ends with 7×7 boards. Version 1.1 added battles, in which up to 16 players race through the same five boards using a six-digit code, step-by-step hints and one free past mission. There is also an endless Unlimited mode, streaks, achievements, a dark mode and a colour-blind palette. It is free with no ads and no account; an optional one-time Pro purchase removes the daily limits on Unlimited and hints, lets you create battles and opens all past missions, and never affects the daily score. The developer, Jaewon Seo, who makes apps alone in South Korea under the name 037, says the code is almost all written by Claude Code. In English, Korean, Japanese, Traditional Chinese, French, German and Spanish.
How it was built
Partially verifiedThe developer's Zenn article says the code is almost entirely written by Claude Code (コードはほぼ Claude Code に書いてもらっています). The developer's own part is solving boards to make sure they do not come down to luck, and working out the solver's rules together with it. The app uses React, TypeScript and Capacitor, with the generator and solver in plain TypeScript. No model is named and no exact share is given.
- DeveloperThe author profile on the same Zenn page: a Korean independent developer making iOS apps such as Sync and Chesspy at the small studio 037, “Claude Codeで開発” (developed with Claude Code). — Zenn (Jaewon Seo / jaewonseo)
React, TypeScript and Capacitor, with the board generator and logic solver in plain TypeScript. Each day's boards are generated on the device from the date as a seed, so every player gets the same 20 boards without downloading them; the solver keeps only boards with a single solution that it can reach step by step, and drops boards whose last piece can only be found by elimination. The Sunday 7×7 boards take minutes to generate, so they are made in advance and bundled. The only backend is a small function that returns the Top % from anonymous scores. The 15-second trailer was rendered frame by frame on a canvas with the game's own board-drawing code, and the sound is synthesised.
- Engine / framework
- None (React and TypeScript with Capacitor)
- Languages
- TypeScript
- Team size
- 1 (solo)Developer ReportedZenn (Jaewon Seo / jaewonseo)
- Development time
- Not disclosed
- Development cost
- Not disclosed
- AI-written code
- Not disclosed
“コードはほぼ Claude Code に書いてもらっています。”Verification notes: AI use comes from the developer's Zenn article (published 5 Oct 2026, Japan time), written in Japanese, which links the App Store listing, and from the author profile on the same page. Apple's lookup data (4 Nov 2026) gives seller 037, bundle id com.seojaewon.ambush, release 30 Sep 2026, version 1.1.1 (11 Oct 2026, UTC), age rating 4+, iOS 16.4 or later and the seven languages; the store text names the Chinese as Traditional. The studio site 037.works/chesspy, which Apple gives as the seller website, links the App Store, Google Play and a browser version on GitHub Pages; the browser build's script talks only to a Supabase function for the Top % ranking, TelemetryDeck analytics and RevenueCat's purchase SDK, and no calls to AI services were found. The article's 1.1 features (battles, hints, past missions, added languages) were released on 5 Oct 2026 per the article. The battle mode is asynchronous: players race the same boards within seven days rather than playing live. On 4 Nov 2026 the Korean App Store showed 3.2 out of 5 from 5 ratings, the US store 5.0 from 2 and the Japanese store none (observed; there is no App Store rating metric). On 5 Oct 2026 the article said Android was in closed testing; on 4 Nov 2026 Google Play listed the game under developer 서재원 with 10+ downloads, in-game purchases and a 3+ rating (observed; Google Play is not a platform we list). The puzzle uses ordinary chess-piece moves, not any third-party IP. The game was not played.
Development history
Released free on the App Store.
OfficialApple App StoreVersion 1.1 adds battles for up to 16 players, hints, one free past mission and Japanese, Traditional Chinese, French, German and Spanish; the developer describes the daily-puzzle generator on Zenn the same day.
DeveloperZenn (Jaewon Seo / jaewonseo)Version 1.1.1: a new tutorial board, tap-to-place when one kind of agent is left, hearts kept when resuming a mission, PERFECT in the shared text, and fixes for small screens (date in UTC).
OfficialApple App Store
Game performance
Each figure measures something different — concurrent players, owners, downloads and sales are never interchangeable and are never added together. Labels show where each number comes from.
App Store (iOS)
Free, with no ads and no account; an optional one-time Pro purchase (no daily limits on Unlimited and hints, creating battles, all past missions, all agent designs and detailed stats) never affects the daily score (store listing, 4 Nov 2026). Requires iOS 16.4 or later. Version 1.1.1.
Not publicly available: Gross revenue.
Browser (official site)
Free in the browser. Whether the optional Pro purchase is offered in the browser version was not checked.
No public metrics recorded for this listing.
Not publicly available: Concurrent players (site), Monthly revenue, Gross revenue.
Reviews & rankings
Not yet reviewed by our editors.
Not currently ranked.
Sources
| Source | Type | Published | Accessed |
|---|---|---|---|
| パズル用のサーバーなしで、世界中のスマホが同じ20盤面を作るデイリーパズルを作った話 Zenn (Jaewon Seo / jaewonseo) · Japanese | Devlog | Oct 5, 2026 | Nov 3, 2026 |
| Chesspy on the App Store (Japan) Apple App Store · Japanese | Store page | Sep 30, 2026 | Nov 3, 2026 |
| 037 — Chesspy (studio site) 037 | Official site | Not confirmed | Nov 3, 2026 |
| Chesspy on Google Play Google Play | Store page | Not confirmed | Nov 3, 2026 |
