Builders of the RefereePro smartphone app are satisfied with use of it during the first official match. An interview from the Dutch Referee Blog with Jaime Herrera, a former Fifa referee from Mexico who helped developing the digital referee signal system. Read also the previous blog “Referee 2.0 uses smarphone app for goals and cards” about the referee smartphone app RefereePro on this blog. It includes a video about how it works. How did the referee prepare for the match? Jaime Herrera: “We have been designing and working on the development of Referee Pro since a year ago and I, as a former FIFA referee, know how to use it…