App Overview

Mahjong Win! icon

Mahjong Win!

Potatso Lab LTD · Entertainment

Japanese Mahjong (Riichi Mahjong) is a popular tabletop game, but its complex rules make it difficult for many players to accurately calculate the number of han and scores

$4.99 · In-app purchases

PRICE
$4.99
In-app purchases
BUSINESS MODEL
Paid
No overall Grossing estimate available
RATING
4.0
3 ratings · Top 30%

Evidence scope: No current overall US chart position is available. Category-chart positions shown in discovery are a separate scope. Revenue is a directional model estimate, not verified earnings.

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What's included16 files

A product spec, phased build plan, differentiation notes, and screen references.

  • START_HERE
  • AGENTS
  • EVIDENCE
  • SPEC
  • BUILD_PLAN
  • DIFFERENTIATION
  • skills/
  • screens/
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Illustrative example: an invoice app for independent contractors. Your kit is tailored to the app you choose; this is not its generated content.

Feature spec

Goal: Send a clear invoice after finishing a job.

  • Add a client, line items, a due date, and payment instructions.
  • Preview the total before exporting a PDF.
  • Keep an editable draft if export fails.

Screen plan

Invoice editor: Client at the top, editable line items in the middle, total and preview action at the bottom.

States: Empty draft, validation errors beside each field, exporting, and a retry action that preserves the draft.

Differentiate and validate

Hypothesis: Contractors need faster repeat invoices more than more templates.

First experiment: Test duplicating a previous job with five contractors. Watch where they hesitate before expanding the feature set.

The full kit adds a phased build plan, evidence notes, tool prompts, and implementation guidance. It is a plan for your coding agent, not a finished app.

Usage: Mechanics are fair game; never reuse the original name, branding, assets, or verbatim copy.

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Good fit for mobile-first iOS and Android prototypes with managed app scaffolding.

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Rork plan preview for Mahjong Win!: map the core Entertainment workflow, choose the smallest differentiated feature set, define the data and monetization boundaries, then prototype the riskiest user journey first.
            

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Opportunities

AI-GENERATED OPPORTUNITY HYPOTHESES

These are generated suggestions, not verified review quotations. Check current App Store reviews and speak with users before treating a possible gap as a requirement.

Hypothesis 1

Introduce more diverse game modes and challenges.

Assumption to check: Limited game modes compared to competitors

Validate with people who use this workflow before building.

Hypothesis 2

Optimize asset loading and use caching.

Assumption to check: Slow loading times for game assets

Validate with people who use this workflow before building.

Hypothesis 3

Add chat or social features for players to interact.

Assumption to check: Lack of community features like chat

Validate with people who use this workflow before building.

Hypothesis 4

Improve navigation flow with clearer labels and organization.

Assumption to check: Difficulty in navigating between game modes

Validate with people who use this workflow before building.

App evidence

Original App Store material. Ratings and screenshots describe the existing app, not proof of demand for your version.

App Store description

Japanese Mahjong (Riichi Mahjong) is a popular tabletop game, but its complex rules make it difficult for many players to accurately calculate the number of han and scores. To solve this problem, we have developed "Mahjong Win! - Smart Japanese Mahjong Helper" to help everyone play face-to-face with friends. Mahjong Win! is a powerful and practical Mahjong assistant app, whose main function is to quickly and accurately calculate the number of han, fu, and scores for players based on photos taken of the playing table. Whether you are a beginner or an experienced player, after using our application, you will be able to enjoy the fun of Japanese Mahjong more conveniently. [Features] • Tile recognition: Using artificial intelligence technology, our app can intelligently recognize the tiles on the photos, including numbers, suits, and wind directions, to ensure accurate display. • Yaku identification: Yaku is an important indicator for calculating scores in Japanese Mahjong. Our application can automatically analyze the player's hand tiles and melds, and quickly identify yakuman based on the rules, allowing you to focus on the game itself. • Number of han and fu: Our application can automatically calculate the number of han and fu based on factors such as tile patterns and yaku, avoiding tedious manual calculations and saving time and effort. • Score calculation: Score calculation in Japanese Mahjong is extremely complicated. Our app can accurately calculate the score for you, making game settlement easier and allowing you to enjoy the joy of winning. [Highlights] • User-friendly interface: Our application has a simple and intuitive user interface, making operations easier and more natural. No need for complicated settings, just take photos to enjoy the convenient services of calculating number of han, fu, and scores. • Powerful tile recognition: Our AI algorithm has been carefully trained to efficiently and accurately recognize common Mahjong tiles. • Extraordinary calculation efficiency: With the built-in efficient AI recognition and calculation engine, our software can run locally quickly, saving a lot of time and allowing you to focus more on the game experience. • Timely updates: Our team will continue to improve and enhance the functionality of the application, adding more auxiliary functions. If you have any suggestions, welcome to communicate with us through the in-app feedback. After using the "Mahjong Win!" assistant, we hope you will experience the great convenience brought by the powerful features of this application. Whether you are a beginner or an expert in Japanese Mahjong, we sincerely hope that "Mahjong Win!" can bring you fun and the joy of success in your game journey, and enjoy pleasant matches with friends!

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Screenshots

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Build scope

Plan a focused first version with your coding agent. These are planning assumptions, not a delivery guarantee.

Define the first version

Choose one audience and one core workflow. Use the kit to agree on its screens, data, and acceptance criteria before building.

Set boundaries

Decide which secondary features, integrations, and platform support can wait. Your version does not need to reproduce everything in the original.

Check the hard parts

Validate external services, specialist technology, data access, and ongoing costs for your chosen scope.

SUGGESTED BUILD STACK
React Native
Expo
Zustand
react-navigation
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@react-native-async-storage/async-storage
BUILD KIT DIFFICULTY
Advanced

From the Build Kit assessment.

A reliable timeline needs an agreed scope and a technical check. Ask your agent to estimate the phases in BUILD_PLAN.md after that review.