# Gengou Lib vs JHP byNSDev

The clearest difference is ads: JHP byNSDev at none against Gengou Lib's shown. JHP byNSDev also leads on update cadence (every 7 months vs every 61 months). Gengou Lib's advantage is iOS requirement (13.0 vs 15.6). On price, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Gengou Lib ships an update every 61 months, JHP byNSDev every 7 months. The most recent releases landed on October 5, 2026 and October 3, 2026 respectively.

## The numbers

| Metric | Gengou Lib | JHP byNSDev |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[2.5 (2 ratings)](https://appshunter.io/ios/app/gengou-lib/id284830543/reviews)** | — |
| Number of ratings | **2** | — |
| Positive reviews | 84.5% of reviews | — |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | Every 61 months | **Every 7 months** |
| Monetization | Free | — |
| Size | 6 MB | 26 MB |
| Requires iOS | **13.0** | 15.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Masayuki Akamatsu](https://appshunter.io/developer/284722836) | [NIHON SYSTEM DEVELOPER CORPORATION](https://appshunter.io/developer/1198103734) |

## What reviewers say

### Gengou Lib

[App page](https://appshunter.io/ios/app/gengou-lib/id284830543)

Quickly convert between Japanese era names and Christian era years. Features include era and year searching, period and era pickers, and the ability to display the current year in either system. Texts can be shown in Japanese or English.

**Highlights:** Era and year search, Period picker, Era picker, Christian era year picker, Japanese era year picker, Show this year button, Multi-language text display

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### JHP byNSDev

[App page](https://appshunter.io/ios/app/jhp-bynsdev/id1244732477)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Gengou Lib free?

Gengou Lib is free to download, with no in-app purchases.

### Is JHP byNSDev free?

JHP byNSDev is free to download, with no in-app purchases.

### Do Gengou Lib or JHP byNSDev have ads?

Gengou Lib shows ads; JHP byNSDev does not.

### Which is updated more often, Gengou Lib or JHP byNSDev?

Gengou Lib ships an update every 61 months, and JHP byNSDev every 7 months. Most recently, Gengou Lib was updated on October 5, 2026 and JHP byNSDev on October 3, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*