---
title: "Gengou — App Overview"
url: https://marlvel.ai/apps/gengou
category: Productivity
developer: Masayuki Akamatsu
platforms: ios
rating: 3.8 (4 ratings)
pricing: paid
report_level: overview
generated: 2026-04-26
last_verified: "2026-04-26T20:09:22.414Z"
---

<!-- SECTION: Key Insight -->
> **Key Insight:** While the app offers niche utility for date conversion, user feedback indicates an urgent need for technical updates to ensure modern iOS compatibility.

<!-- SECTION: Quick Facts -->
| Metric | Value |
|--------|-------|
| Category | Productivity |
| Rating | 3.8 ★ (4) |
| Pricing | paid |
| Platforms | iOS |
| Latest Version (iOS) | 3.0.0 |
| Developer | Masayuki Akamatsu |

<!-- SECTION: Summary -->
## What is Gengou?

Gengou is a utility tool designed to convert between the Japanese era system and the Christian calendar. It provides specialized pickers and search functions to assist users in navigating historical and administrative date formats, including support for the Nanboku-chō period.

<!-- SECTION: Key Features -->
## Key Features

- **Conversion Pickers**: Includes dedicated pickers for periods, eras, Christian years, and Japanese era years.
- **Language Localization**: Allows users to toggle between Japanese and English text independently of system settings.
- **App Badge Integration**: Displays the current year in either Japanese or Christian era format directly on the app icon badge.
- **Quick Reference Search**: Provides a search function for era names and specific years, including historical parallel era schemes.

<!-- SECTION: Target Audience -->
## Who is it for?

Professionals working with Japanese government agencies, municipal offices, or corporations requiring precise date conversions.

<!-- SECTION: Links -->
## Links

- [App Store](https://apps.apple.com/us/app/gengou/id288968943?uo=4)
- [Full Intelligence Report](https://marlvel.ai/apps/gengou)

---
*This is an overview report. Sentiment analysis, competitive landscape, and SWOT analysis are available in the [full intelligence report](https://marlvel.ai/apps/gengou).*
*Generated by [Marlvel.ai](https://marlvel.ai) — Independent app intelligence.*