Knowing the future is saving future lives. In Japan, the threat of natural disasters is a part of everyday life. Each year, Japan experiences more than 5000 earthquakes greater than magnitude 3 and more than 20 typhoons. As the country's most visited website, Yahoo!JAPAN has been strongly committed to disaster prevention. After the Great East Japan Earthquake of 11 March 2011, we formed a task force to focus on this issue. The team developed the "Disaster Alert App". There are three key features to this app; speed, personalization, and the 8-pack disaster alerts.

First, users can receive alerts faster than a disaster actually reaches them. For example, if an earthquake takes place 50 km off shore the alert will be delivered 5 seconds before it reaches the inland users. For a volcanic eruption, users will be alerted three days in advance; for hurricanes, four hours in advance, and for tsunamis, thirty minutes in advance.

Second, the app is carefully designed so that users only receive relevant and vital information. Once installed, the GPS automatically detects the user's location down to their district. Users can then personalize the app by setting other locations such as their home and office. This enables us to send alerts which affect the locations important to our users. Users can also set the relevant threat level and frequency for receiving alerts so they are only notified of a threat if the situation becomes more serious.

Third, it’s the world's first app to have information and alerts for eight different types of disasters: earthquakes, heavy rain, tsunamis, weather warnings, volcanic eruptions, radiation, electricity consumption, and scheduled blackouts.

In a year since its release, our app has ranked 1st in its AppStore category. With coverage on more than 30 media outlets, it has created a huge buzz on Twitter and the blogosphere. During a disaster drill in central Tokyo, it was instrumental in achieving an evacuation rate of 100%.

But our goal isn’t simply to gain media attention. Our real goal is to help prevent future disasters, and what really matters to us is the number of lives we can help save. Experts estimate that the death toll could reach 320,000 if a major tsunami hits the densely populated areas of Japan. Our app has been downloaded 1.3 million times so far. This means we are watching out for 1.3 million lives.