VAT Calculator, created by Joao Ferreira, is a free application available on Android that provides a comprehensive calculator for VAT, GST, HST, PST, and Consumption Tax. The calculator includes all European Union countries and many others with their respective tax rates. It also allows the creation of custom rates for the case you want another type of calculations, such as discounts, fees, or for a country not listed yet. The application has three screens, and the values and calculations made in one of them are automatically reflected in the others. If you want to suggest a country or language, the developer provides a simple form on their blog. The application is user-friendly and useful for businesses and individuals who need to calculate VAT or similar taxes accurately.