(Thanks to Atid-EDI) Israel’s Haifa Group is a global leading supplier of potassium nitrate for agriculture and industry, specialty plant nutrients and food phosphates. It has just launched a free mobile app (iOS or Android) that helps the grower determine the precise amount of fertilizers needed.
http://www.haifa-group.com/about_haifa/news_and_events/fertimatch_app_pr.aspx