AppSLD is a computer tool designed to immediately evaluate the transverse dimensions of fuel discharge that prevents the spread of fire based on the energy conditions with which the flame front makes contact with the edge or border between the occupied area. by the vegetation and the non-combustible zone (mineral soil, road pavement). Likewise, it incorporates a physical-mathematical calculation algorithm for testing the effectiveness of said infrastructures, also providing information on the amount of energy received at a certain distance from the flame front and, based on this, the safety distance for the combatants. . The programmed algorithms respond to the transmission of energy by radiation and convection.