# PREP（プレップ） vs Japan Alerts

The clearest difference is rating: Japan Alerts at 4.4 against PREP（プレップ）'s 2.3. Japan Alerts also leads on update cadence (every 5 days vs every 6 weeks) and ratings volume (18 vs 6). PREP（プレップ）'s advantage is review sentiment (29% vs 20%). On price, ads, in-app purchases and monetization model 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 and Japan Alerts sells 1 in-app purchase, starting at $7.99 per year. Whichever you choose, the download price is not the number that matters.

Japan Alerts holds the better App Store score, 4.4 against 2.3. Both are backed by a comparable volume of ratings — 6 and 18 respectively. Written reviews complicate that: 29% of PREP（プレップ）'s written reviews are positive against 20% of Japan Alerts's, so the app with the better star average is not the one people write more warmly about.

PREP（プレップ） ships an update every 6 weeks, Japan Alerts every 5 days. The most recent releases landed on October 14, 2026 and October 11, 2026 respectively.

## The numbers

| Metric | PREP（プレップ） | Japan Alerts |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [2.3 (6 ratings)](https://appshunter.io/ios/app/prep/id398954883/reviews) | **[4.4 (18 ratings)](https://appshunter.io/ios/app/japan-alerts/id6759379739/reviews)** |
| Number of ratings | 6 | **18** |
| Positive reviews | **29.1% of reviews** | 20.0% of reviews |
| In-app purchases | Yes | Yes |
| Ads | Yes | Yes |
| Update frequency | Every 6 weeks | **Every 5 days** |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 90 MB | 127 MB |
| Requires iOS | **15.0** | 15.1 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [RC Solution Co.](https://appshunter.io/developer/398954886) | [Itchigoo](https://appshunter.io/developer/372170918) |

## 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 |


### Japan Alerts

[App page](https://appshunter.io/ios/app/japan-alerts/id6759379739)

Receive real-time alerts for earthquakes, tsunamis, volcanoes, and typhoons directly from Japan's official meteorological agency. Features include S-wave countdowns, municipality-level evacuation orders, and multi-language support for essential information.

**Highlights:** Real-time earthquake, tsunami, volcano, and typhoon alerts, S-wave countdown for shaking arrival, Municipality-level evacuation orders, Multi-language translation of alerts and place names, Interactive map with hazard layers and shelters, Family safety group and check-in features, Offline access to shelter information

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Annual Subscription | $7.99 | per year |


## 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 Japan Alerts free?

Japan Alerts is free to download, with in-app purchases available.

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

Japan Alerts is rated higher. PREP（プレップ） averages 2.3 out of 5 from 6 ratings, while Japan Alerts averages 4.4 from 18 ratings.

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

Both PREP（プレップ） and Japan Alerts show ads.

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

PREP（プレップ） ships an update every 6 weeks, and Japan Alerts every 5 days. Most recently, PREP（プレップ） was updated on October 14, 2026 and Japan Alerts on October 11, 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.*