The web version of Marlo Diagrams is an innovative ICT tool that can be run on computers, mobile phones and graphics tablets to graphically represent and solve logic problems. There are multiple classical examples and more than one hundred proposed exercises of logic. It can be an useful tool in the development of critical thinking, by favoring heterogeneous forms of reasoning through the coordination and integration of verbal and visual inferences. https://fersoler.github.io/MarloDiagrams/ The creators of Marlo diagrams believe that this tool allows for a greater integration of verbal and diagrammatic reasoning than Venn diagrams. And this is so because these diagrams show each of the steps that must be taken to get from the premises to the conclusion without committing the usual fallacies of affirming the consequent and denying the antecedent.Marlo diagrams are a renewed version of the doctrine of the quantification of predicates, very popular in the nineteenth century, and allow us to recover the middle term as the basis of any propositional calculus inference. Proceeding in this way we bring logic closer to the common sense of students.