Calculadora de Materiales is a free Android app developed by Soluciones RUVI. It is a utility and tool app that helps in the calculation of materials required for preparing concrete. This app is designed for the "Do it yourself" system, and it is a useful tool for people who do not always have a concrete mixer at hand.

The calculations of materials in this app are based on 19-liter cans and cement in bags (sacks) of 50 Kg. It is easy to use and provides accurate results. The app is perfect for people who want to prepare concrete for their projects but do not know how much material they need.

Overall, Calculadora de Materiales is a simple and effective app that serves its purpose well. It is highly recommended for anyone looking for a reliable tool to calculate the materials required for preparing concrete.