「あんっ」とイって！
An adults-only party game for one phone: everyone says the same word, each acting a secret risqué situation, and the others guess who had which. Built with Claude Code and spec-driven development.
Links go to the official store or developer page. Last verified Nov 7, 2026.
Age rating: 18+
Japanese App Store age rating 18+ for frequent crude humour or profanity, frequent mature or suggestive themes, frequent sexual content or nudity, and infrequent references to alcohol, tobacco or drugs (store page, 7 Nov 2026); Apple's lookup data gives 17+. The developer's article warns that it contains dirty jokes (下ネタ). (Apple App Store (seller: Tsubasa Shinohara))
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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
Install from Apple's App Store on an iPhone or iPad.
Mobile · Apple App Store (seller: Tsubasa Shinohara)
About 「あんっ」とイって！
「あんっ」とイって！ is a free iPhone party game for three to eight players around one phone, rated 18+ on the Japanese App Store. Each round shows a word (for example 「いやん〜」), every player is secretly given a numbered situation, and each says the same word acting their situation; the others then guess who had which. All the situations are what the developer calls “pink”, sexual innuendo meant for drinking parties and trips with friends, and the developer's article warns that it contains dirty jokes. A game takes from about five minutes; it works offline, needs no account, and the developer says it borrows the system of an existing board game without naming it. The developer, Tsubasa Shinohara, a web engineer, built it with Flutter and Claude Code using spec-driven development and wrote it up for the Qiita “クソアプリ” (joke app) Advent Calendar 2025: the cc-sdd tool turned a prompt into a specification, requirements and a task list, and Claude Code carried out the tasks one by one, with the frontend-design plugin for Claude Code guiding the look. The developer reports a few hours of development, then three to four days of App Store setup and review before release. Free, with ads.
How it was built
VerifiedPer the Qiita article (20 Dec 2025), the developer used Claude Code (Max 5x plan) with cc-sdd for spec-driven development: a prompt describing the game, the Flutter and Riverpod stack and the screens went to cc-sdd, which produced the specification, requirements and a task.md list; the developer adjusted the tasks and Claude Code implemented them one at a time (“cc-sddは詳細なタスクをtask.mdで出力してくれて、それをこちらで手を加えつつ細かく実装してくれる”), and “上記を実行してもらうだけでアプリが完成します！” (just having it run these, the app is finished). The frontend-design plugin for Claude Code shaped the visual design. Errors were fixed by passing the error message back with a fix request. The developer also thought up many of the prompts (お題) together with Claude.
The developer used Cursor as the editor, whose completions helped when changing the source by hand (“手動でソースを変えてももちろんOK”).
Front-end-only Flutter (Dart) app for iOS with Riverpod, freezed, google_fonts and confetti; no back end, no saving, fully offline. Spec-driven development with cc-sdd: specification, requirements and task breakdown generated from one prompt, then implemented task by task by Claude Code, with the frontend-design plugin for the pastel look. App Store setup (privacy policy, preview images, icon, ads, description) and review took three to four days after a few hours of development.
- Engine / framework
- Flutter
- Languages
- Dart
- Team size
- Not disclosed
- Initial build time
- A few hours of development, then 3–4 days until release on the App StoreDeveloper ReportedQiita (tsubasaaa_1234)
- Development time
- Not disclosed
- Development cost
- Not disclosed
- AI-written code
- Not disclosed
“上記を実行してもらうだけでアプリが完成します！”Verification notes: AI use, tools and timings come from the developer's Qiita article (20 Dec 2025, 21:43 JST; day 20 of the クソアプリ Advent Calendar 2025), re-read with its Markdown source on 7 Nov 2026; it links the App Store page. Store facts come from the Japanese App Store page and Apple's lookup data (7 Nov 2026): seller Tsubasa Shinohara, release 16 Dec 2025 (08:00 UTC), version 1.0 of 17 Dec 2025, free, iOS 13 or later, category Board, contains ads, 5 out of 5 from 1 rating (observed; there is no App Store rating metric, so it is not recorded as one). The article says the app was released on 17 Dec; Apple's data gives 16 Dec as the release date and 17 Dec for the current version, so the store date is used. The store lists English (EN) as the only language, but the title, description, screenshots and prompts shown are Japanese; the in-app language was not checked; the language entry records Japanese from the store description and the prompts shown in the developer's article. The article says running the generated tasks finishes the app and also shows the developer editing code by hand with Cursor completions; it gives no code share. The developer says the game's system is an homage to an unnamed board game; no name, artwork or text of another game appears in the sources, so no IP notice is recorded. The app was not checked for AI service calls; the article describes no AI used during play. The developer's own site is tsubasa-oi.github.io (store seller URL). The game was not played.
Development history
Released free on the Japanese App Store (Apple's lookup data); version 1.0 dated 17 Dec 2025.
The developer's Qiita article for the クソアプリ Advent Calendar 2025 describes building the app with Claude Code and cc-sdd.
DeveloperQiita (tsubasaaa_1234)
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 on iPhone and iPad (iOS 13 or later) in the Japanese App Store; the listing says it contains ads. Rated 18+ on the store page (17+ in Apple's lookup data).
Not publicly available: Gross revenue.
Reviews & rankings
Not yet reviewed by our editors.
Not currently ranked.
Sources
| Source | Type | Published | Accessed |
|---|---|---|---|
| ClaudeCode×仕様駆動開発でピンク♡なボードゲームを作ってみた Qiita (tsubasaaa_1234) · Japanese | Devlog | Dec 20, 2025 | Nov 3, 2026 |
| 「あんっ」とイって！ (App Store) Apple App Store (seller: Tsubasa Shinohara) · Japanese | Store page | Dec 16, 2025 | Nov 3, 2026 |
| Official game page (language check) Tsubasa Shinohara | Official site | Not confirmed | Nov 3, 2026 |
