# PREP（プレップ） vs WeatherJapan

The clearest difference is rating: WeatherJapan at 3.0 against PREP（プレップ）'s 2.3. WeatherJapan also leads on in-app purchases (none vs 2) and review sentiment (40% vs 29%). PREP（プレップ）'s advantage is update cadence (every 6 weeks vs every 4 months) and ratings volume (6 vs 2). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. PREP（プレップ） sells 2 in-app purchases, starting at $0.99 per month. WeatherJapan asks for nothing beyond the download.

WeatherJapan holds the better App Store score, 3.0 against 2.3. Both are backed by a comparable volume of ratings — 6 and 2 respectively. Written reviews point the same way: 29% of PREP（プレップ）'s written reviews are positive against 40% of WeatherJapan's.

PREP（プレップ） ships an update every 6 weeks, WeatherJapan every 4 months. Both last shipped on September 23, 2026.

## The numbers

| Metric | PREP（プレップ） | WeatherJapan |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [2.3 (6 ratings)](https://appshunter.io/ios/app/prep/id398954883/reviews) | **[3.0 (2 ratings)](https://appshunter.io/ios/app/weatherjapan/id1244002532/reviews)** |
| Number of ratings | **6** | 2 |
| Positive reviews | 29.1% of reviews | **40.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | Yes | Yes |
| Update frequency | **Every 6 weeks** | Every 4 months |
| Monetization | Free with in-app purchases | **Ad-supported** |
| Size | 90 MB | 24 MB |
| Requires iOS | **15.0** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [RC Solution Co.](https://appshunter.io/developer/398954886) | [sorakaze Inc.](https://appshunter.io/developer/1046448101) |

## What reviewers say

### PREP（プレップ）

[App page](https://appshunter.io/ios/app/prep/id398954883)

This app provides real-time disaster information based on your current location, including alerts for earthquakes, tsunamis, and heavy rain. It helps you plan for disasters by allowing you to set action plans and share information with family members. The app also offers guidance during emergencies to ensure safe actions.

**Highlights:** Real-time disaster information by location, Disaster action planning, Emergency guidance, Family information sharing, Various disaster alerts (earthquake, tsunami, rain, etc.), Precipitation forecast timeline

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| PREP Premium Service | $0.99 | per month |
| PREP ファミリーサービス | $3.49 | per month |


### WeatherJapan

[App page](https://appshunter.io/ios/app/weatherjapan/id1244002532)

Get detailed weather forecasts for Japan, including hourly and daily predictions for up to 48 hours and a week ahead. View current and surrounding area conditions on a map, with temperature graphs and sunrise/sunset times. Supports Celsius and Fahrenheit.

**Highlights:** Hourly forecasts up to 48 hours, Daily forecasts up to one week, Temperature graphs, Sunrise/sunset times, Map view of surrounding areas, Search locations by name, Celsius/Fahrenheit support

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is PREP（プレップ） free?

PREP（プレップ） is free to download, with in-app purchases available.

### Is WeatherJapan free?

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

### Which has better reviews, PREP（プレップ） or WeatherJapan?

WeatherJapan is rated higher. PREP（プレップ） averages 2.3 out of 5 from 6 ratings, while WeatherJapan averages 3.0 from 2 ratings.

### Do PREP（プレップ） or WeatherJapan have ads?

Both PREP（プレップ） and WeatherJapan show ads.

### Which is updated more often, PREP（プレップ） or WeatherJapan?

PREP（プレップ） ships an update every 6 weeks, and WeatherJapan every 4 months. Most recently, PREP（プレップ） was updated on September 23, 2026 and WeatherJapan on September 23, 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.*