EVAPO: A smartphone application to estimate potential evapotranspiration using cloud gridded meteorological data from NASA-POWER system

•EVAPO is the state-of-the-art app applied in agricultural or hydrological problems.•EVAPO is an app ready-to-use in practical situations where there is a scarcity of water.•EVAPO app is reliable because uses Penman-Monteith method to estimate potential evapotranspiration worldwide. In this study a new android app for smartphones to estimate potential evapotranspuration (PET) in real time, using gridded data from NASA-POWER, to any location in the world, would result in a more efficient irrigation and increase irrigation water conservation. The smartphone app called EVAPO uses meteorological data to calculate PET using the Penman–Monteith (FAO56) method. To evaluate performance of the proposed method, we compared PET estimated by the EVAPO with that estimated from climatic data from conventional surface meteorological stations. The accuracy, tendency and precision of the models were determined using the Willmott et al. (1985) concordance index (d), systematic root mean square error (RMSEs) and determination index (R2), respectively. The results obtained were satisfactory for all studied locations whit mean values of 0.67, 0.95 (mm) and 0.72 for d, RMSEs and R2, respectively. The app can be accessed in the Play Store (free): https://play.google.com/store/apps/details?id=br.com.maldonado.instantet0.