A current problem in the chemical control of late-season soybean diseases (LSD) is the lack of scientific guidelines to determine whether or not a fungicide application is needed, and if needed, to further determine a better fungicide application timing. To help in that decision process, Carmona et al. developed a scoring system (SS) based on weather, disease pressure, and other factors that are useful in estimating the probability of expected net return to fungicide treatment. Based on the SS, we developed an Android™ app named AgroDecisor EFC. In the app, the factors from which the SS stems are presented to users for them to quickly select available options to obtain a guiding recommendation on whether or not to apply a fungicide within the R3-R5 soybean growth stages. Scoring greater than 33 indicates a higher probability of obtaining a positive yield response, whereas scoring below 23 indicates no expected response and thus no need for fungicide applications. Intermediate values indicate that the application of fungicides would produce uncertain results thus detailed analysis of risk factors would be required. The app also provides a weather prediction system for the location where the device is located (according to the GPS receiver). The AgroDecisor EFC can help farmers and crop consultants assess the risk of LSD epidemics as well as yield and economic response from foliar fungicide applications. The AgroDecisor EFC smartphone/tablet application will be available in the near future and can be downloaded at no cost from the Google Play™ website (https://play.google.com/store/apps/details?id=mapplics.sistemadedecision.soja&hl=en) to any phone that has the Android™ system.