The app shows the present water level and the hourly forecast for the next two days of one hundred locations along the great rivers and coasts in the Netherlands, using measurements and forecasts from the Dutch authority Rijkswaterstaat. Users can select locations, water levels and uncertainty levels for which they want to receive a notification. In the free version of the app information is provided for five locations. In the pro version (2,99 Euro) access is provided to all one hundred locations. An incompany version of the app is also easily available in the Netherlands or abroad, where the app is based on own (local) water level measurements and forecasts.