NERV Disaster Prevention 4+

All you need, in one app

Gehirn Inc.

    • 4.5 • 8 Ratings
    • Free
    • Offers In-App Purchases

iPhone Screenshots


The NERV Disaster Prevention App is a smartphone service that delivers earthquake, tsunami, volcanic eruption and emergency warnings, as well as provides weather-related disaster prevention information for flooding and landslides, optimised based on the user's current and registered locations.

The app was developed to help people living in or visiting an area where damage is expected to occur, to accurately assess the situation and make quick decisions and actions.

With information received directly through a leased line connected to the Japan Meteorological Agency, our proprietary technology enables the fastest information distribution in Japan.

▼ All the information you need, in one app

Get a wide range of disaster prevention information, including weather and typhoon forecasts, rain radar, earthquake, tsunami and volcanic eruption alerts, emergency weather warnings and landslide information, river information, and heavy rain risk notifications.

By interacting with the map on the screen, you can zoom in on your location or pan across the country and see the cloud cover, typhoon forecast areas, tsunami warning areas, or the scale and intensity of an earthquake.

① Providing users with the most appropriate disaster information

The home screen displays the information you need at the time and place you need it. When there’s an earthquake, the home screen will show you the latest information. If another type of warning or alert is issued while the earthquake is active, the app will sort them depending on the type, elapsed time and urgency, so you’ll always have the most important information at your fingertips.

② Push Notifications for Important Information

We send out different types of notifications depending on the device’s location, the type of information and level of urgency. If the information is not urgent, we send a silent notification as not to disturb the user. For more urgent situations where a disaster is time-sensitive, a ‘Critical Alert’ alerts the user to an imminent danger. Notifications like Earthquake Early Warnings (Alert level) and Tsunami Warnings will be forced to sound, even if the device is in Silent or Do Not Disturb modes.

Note: Critical Alerts will only be sent to users in the target area of the most urgent types of disasters. Users who have registered their location but are not in the target area will instead receive a normal notification.

※ In order to receive Critical Alerts, you need to set your location permissions to “Always Allow” and have Background App Refresh turned on. If you don’t want Critical Alerts, you can disable them from Settings.

③ Barrier-Free Design

We paid close attention when designing the app to ensure our information is accessible to everyone. We put a focus on accessibility, with colour schemes that are easy to distinguish for people with colour blindness, and use a font with large, clear letters so long bodies of text are easy to read.

▼ Supporters’ Club (In-App Purchase)

In order to keep doing what we do, we’re looking for supporters to help us cover the development and operational costs of the app. The Supporters’ Club is a voluntary membership scheme for those who want to give back to the NERV Disaster Prevention app, by contributing to its development with a monthly fee.

You can find out more information about the Supporters’ Club on our website.


Gehirn Inc. is an information security company. The security and privacy of our users is our highest priority. We take great care not to collect excessive amounts of information about our users through this application.

Your exact location is never known to us; all location information is first converted to an area code used by everyone in that area (like a zip code). The server also doesn’t store past area codes, so your movements cannot be tracked.

Learn more about your privacy on our website.

What’s New

Version 4.4.0

Added a new River Water Level feature

In this update, we've added a new 'River' layer. With the River layer, you can check the water levels at the monitoring stations and risk management-type water level gauges, updated every 10 minutes.

- Display Method
You can access this by selecting the 'River' layer from the layer switching button on the 'Radar' tab. It overlays water level information on the flood damage layer of the risk distribution.

- Supports Push Notifications
We will promptly notify you via push notifications if the water level at a nearby monitoring station exceeds the flood risk level in your current or registered location. Monitoring stations with water levels above the warning level are also displayed on the home tab.

- About Flood Risk Water Level
The flood risk water level is a guide for issuing evacuation instructions. If the water level at a nearby monitoring station reaches the flood risk level, please ensure your safety by making your own judgment, without waiting for evacuation instructions from local government.

To our supporter members
We truly appreciate your consistent support.
Acquiring river water level data is an extremely high-cost endeavor, which has increased our operating costs by nearly 3 million yen annually. The ability to purchase such data has been made possible thanks to our supporting members. Moreover, the acquired data cannot be utilized in its original form, requiring us to organize and process it for ease of use. This necessitated considerable time and effort in preparation for this release, and we faced numerous challenges along the way. With a forecast of heavy rain, our development team worked at a breakneck pace to finalize the implementation for release.
Now that we've finally released this feature, we sincerely hope you will make good use of it in the coming rainy season, and regularly check the river conditions.

As it's the rainy season, please not only take care against weather disasters but also food poisoning. We wish you all safety and good health.

Ratings and Reviews

4.5 out of 5
8 Ratings

8 Ratings

Kolbe I-Tunes ,

Good but…

I live in the US. So it’s impossible to get notified for a Japanese earthquake. I study the earthquakes there and this would be a better app if you could receive notifications without having to be in Japan. Otherwise it’s well built and pretty stable

Kevin A.J. ,

Great app

Highly recommended if you live in Japan. It has a simple design and easy to understand. Wish I would of had this app when I first got to Japan!

Peeperbean ,


Excellent app however being from the United States, it would be nice if we could change the temperature from Celsius to Fahrenheit in the settings.

App Privacy

The developer, Gehirn Inc., indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Linked to You

The following data may be collected but it is not linked to your identity:

  • Location
  • Diagnostics

Privacy practices may vary, for example, based on the features you use or your age. Learn More

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