GrünZeit is an Android app developed by Verbraucherzentrale Schleswig-Holstein e.V. to help users find out when local fruits, vegetables, salads, and herbs are in season. The app's main feature is its traffic light-colored symbols, with red indicating high energy consumption, yellow indicating medium energy consumption, and green indicating very low energy consumption and corresponding climate impact. The app also provides information on the climate impact of long-distance food transports and domestic production outside of the season.

The content of the GrünZeit app corresponds to the paper version of the seasonal calendar "Heimatisches Obst und Gemüse," which was developed in a joint campaign by all consumer advice centers. The app has been expanded to include some types of vegetables and the category herbs. As usual, there is an overview of all domestic foods considered as well as a list by month in which the climate impact can be read. With this app, users can make informed decisions about their food choices while supporting local produce and reducing their carbon footprint.