# Larko — 6D App Store Optimization (ASO) & Policy Guard Engine

> Larko is a deterministic, cross-platform App Store Optimization (ASO) audit and metadata compliance engine built for mobile development studios and indie developers deploying to Apple App Store and Google Play Store.

## Overview & Philosophy
- **Deterministic Evaluation**: Replaces unverifiable "AI black box" rankings with exact arithmetic, official store API responses, and direct citations of store review guidelines.
- **6-Dimensional Audit (6D Scoring)**:
  1. Title & Identity (Length, brand keywords, repetition).
  2. Subtitle / Short Description (Indexing character utilization).
  3. Description & Long-form Keywords (Google Play 4,000-char indexing vs Apple conversion copy).
  4. Visual Assets & Screenshots (Minimum counts, aspect ratios, feature graphics).
  5. Policy & Rejection Guard (Apple App Review Guidelines 2.3 & Google Play Metadata Policies).
  6. Ratings & Review Sentiment Dynamics.
- **Zero-Signup Free Access**: Complete 6D audit reports, keyword packers, and policy scanners are free, unlimited, and accessible without account creation or credit cards.

## Core Tools & Utilities
- [6D ASO Listing Audit](https://larko.ai/check): Instant audit of any iOS App Store or Google Play Store application across 173 localized storefronts.
- [100-Byte iOS Keyword Packer](https://larko.ai/tools/keyword-packer): Calculates UTF-8 byte weights (Latin ASCII = 1 byte, Cyrillic = 2 bytes, Emoji = 3–4 bytes), eliminates keyword cannibalization from Title/Subtitle, and packs 100% of Apple's 100b field.
- [Store Policy & Rejection Guard](https://larko.ai/tools/policy-guard): Scans copy against Apple Guideline 2.3 (rival platforms, pricing claims, unprovable claims) and Google Play Policies (emojis in titles, caps lock, banned terms 'best/free/#1').
- [Cross-Store Sync & Parity](https://larko.ai/cross-store): Synchronous side-by-side comparison of iOS and Android listings for Flutter and React Native cross-platform apps.
- [Engineering Methodology](https://larko.ai/methodology): Full disclosure of formulas, UTF-8 byte calculations, and scoring thresholds.

## Key Technical Specifications

### Apple App Store
- **Title**: Maximum 30 characters.
- **Subtitle**: Maximum 30 characters.
- **Keywords Field**: Maximum 100 bytes (UTF-8 encoded). Words in Title and Subtitle should not be repeated in Keywords.
- **Guideline 2.3.10**: Strict prohibition of competitor platform references (e.g. "Android", "Google Play", "APK") in metadata and screenshot frames.
- **Guideline 2.3.7**: Pricing claims (e.g. "Free", "Sale") are forbidden in app titles.

### Google Play Store
- **App Title**: Maximum 30 characters. Emojis, exclamation marks, ALL CAPS, and performance/pricing claims ("Best", "#1", "Free") are strictly prohibited.
- **Short Description**: Maximum 80 characters (indexed for search).
- **Full Description**: Maximum 4,000 characters (indexed for keyword search by Google algorithm).
- **Feature Graphic**: Required 1024×500 PNG/JPEG for featured store placement.

## Engineering Knowledge Base & ASO Guides (Blog)
- [Apple Guideline 2.3.10 Rejection Fix Guide](https://larko.ai/blog/apple-guideline-2-3-10-avoid-rejections): Detailed breakdown of rival platform mentions (Android, Google Play), hardware mockups in screenshots, and What's New traps.
- [iOS 100-Byte Keyword Field Optimization Guide](https://larko.ai/blog/ios-100-byte-keyword-field-optimization-guide): UTF-8 byte calculations, Cyrillic 2-byte weight, zero cannibalization, and 100-byte packing algorithms.
- [Google Play Metadata Policy Rules (2026)](https://larko.ai/blog/google-play-metadata-policy-rules-2026): Prohibitions on emojis, caps lock, pricing terms ('Free', 'Best', '#1'), and 80-char Short Description indexing.
- [Cross-Store ASO Strategy for Flutter & React Native](https://larko.ai/blog/cross-store-aso-parity-flutter-react-native): Dual-store publishing, description indexing asymmetry (Apple 0 vs Google 4k), and keyword gap detection.
- [Apple Custom Product Pages (CPP) Strategy](https://larko.ai/blog/apple-custom-product-pages-cpp-aso-strategy): 35 tailored App Store landing pages, Apple Search Ads keyword alignment, and conversion rate optimization.
- [In-App Events & Promotional Content Guide](https://larko.ai/blog/in-app-events-promotional-content-play-aso): Search result card expansion, seasonal keyword indexing, and live-ops retention mechanics.

## Studio & Authorship
- **Developed By**: DriveCode Team (mobile development studio specializing in high-performance Flutter and native applications).
- **Live Dogfooding Portfolio**: Cosmo Color Sort (Grade A 90/100), Cosmo Block Puzzle, Cosmo Solitaire, Cosmo Sudoku.
- **Website**: https://larko.ai
- **Contact & Support**: support@larko.ai