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NERV Disaster Prevention

by Gehirn Inc.

  • Weather
  • Free
  • Small & simple · 93
View on the App Store
Rating
4.7
47 ratings · US storefront
Top 78%among 130 Weather apps
Last update
Sep 17, 2026
Version 7.1.0
Size
79 MB
Category
Weather
Tracked since
Oct 9, 2026

Estimated revenue

A model estimate with a likely range, not a reported figure.

No estimate. Apps outside the grossing charts, and some countries, have no reliable rank-to-revenue curve, so we show nothing rather than a guess.

How this estimate is made

Rank: we take the app's best Top Grossing rank on the latest chart day. Category ranks are converted into an equivalent overall rank, because a #10 in Finance earns far less than a #10 overall.

Curve: that equivalent rank is read off a rank-to-revenue curve anchored on public company revenue and market-data reports for the US iPhone App Store.

Country: the curve is scaled per country (Japan is roughly a third of the US, Türkiye under 1%). Where we have no scale, such as China, there is no estimate.

Range: the likely range widens with country, category and chart depth. It is a plausible span, not a statistical confidence interval.

Not included: ads, payments outside the App Store, and any difference between gross sales and what the developer keeps. Low confidence means indirect data; medium means several independent sources agree.

Full method

Screenshots

As shown on the App Store listing.

About this app

Text from the App Store listing.

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.
https://nerv.app/en/supporters.html

[Privacy]

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.
https://nerv.app/en/support.html#privacy

What’s new

Release notes for the latest version, as written by the developer.

v7.1.0
  • Weather Flash Reports and Weather Information now display a map tailored to the type of information being reported
  • Weather Flash Reports and Weather Information can now be delivered as push notifications

(Weather Information notifications can be disabled in Menu > Notifications)

  • The “Synoptic Chart” layer that was previously offered through Early Access is now available to everyone!

Our thoughts are with everyone affected by the heavy rain disasters occurring across Japan. We hope you’ll be able to get back on your feet, in both body and mind, as soon as possible.

◆ Development Team Update

On August 30, the development team participated in the Miyagi Prefecture Comprehensive Disaster Prevention Drill together with the NERV Disaster Response Vehicle. It unfortunately rained that day, but many people still came out to see us, with visitors stopping by to tell us “I use the app!” and “I saw you on X, so I came to visit!” Some even joined the Supporters’ Club on the spot, reminding us once again just how much support we receive from all of you.

With the recent days of heavy rain, Emergency Warnings have been issued frequently late at night, and our team has had many sleepless days working around the clock.

This update improves how we handle Weather Information reports, linear rainband information, Record-Breaking Short-Period Heavy Rainfall information, and others. We hope this makes the app more useful the next time heavy rain comes around.

Rank history

Daily position in the France charts. #1 is at the top.

Best rank
#56
Current rank
#75
Days charting
7 of 7

On the charts today

Small & simple score

How realistic it is for a small team to build something like this.

93/100

Small & simple

  • Developer size100% · 25

    Developer: 1 app on the charts

  • Audience size100% · 20

    Ratings: 47

  • App size60% · 10

    Size: 79 MB

  • Price model80% · 15

    Price model: free with in-app purchases

  • Demand proof100% · 30

    Best rank #1, 95 countries

An indicator, not a fact. We can't see team size. Calculated Oct 25, 2026 · method i2

How the score works

Version history

  • 7.1.0LatestReleased Sep 17, 2026