A free app for Android, by Robux Calc Free.

Want to buy the perfect avatar store item but don’t have enough robux? Thinking of adding more robux to your account but are in a budget? Then this is the app for you. With this app you can calculate the needed USD and convert it to robux. With this easy to use and beautifully designed app, you can now budget your allowance to your robux buying needs.

This is not a way to gain free robux, instead it is a tool to calculate the conversion rate for your money to robux. This app is lightweight and easy to use and not affiliated with Roblux officially.