The app is completely secure for downloading. Matheus Piscioneri is the official developer of Regra de 3 that can be found in the Tools category. This application has the overall rating 4.5 on Google Play.
The latest update of Regra de 3 was released on Apr 15, 2016 and the app has been installed by over 50K users. This application has adverts. Take the opportunity to download the setup package of Regra de 3 1.1 for free and have a look at users' reviews on Droid Informer. The app is created for Android 4.0.3 and higher.