The Manejo-Matte app is a tool for the diagnosis of planted yerba-mate groves. Its theoretical basis is the Erva 20 production system, which helps to increase the quality and productivity of commercial plantations. The app works based on plantation information provided by the user; turns them into indexes; and draws up a report with the diagnosis in a graphical form. In addition, it indicates which management practices limit the productivity of the yerba-mate trees, referring the user to the Erva 20 System Manual, published at Embrapa Infoteca. The app was developed for smartphones and tablets with an Android operating system.