This mHealth application intent is to provide and empower mobile regular users and health professionals with the tool with which they can estimate their or others visual acuity, based on a classical Snellen Chart Test. This App is innovative because it transforms an old style poster test design in a new, modern, intuitive, ubiquitous test. One App with a simple user interface, and an intuitive navigation chart using swipe gestures to navigate from optotype to optotype, and with the capability to