SAO Calculator Extension is a paid Android app developed by Xlythe, available for 99 cents after downloading. The app is a calculator that can be quickly launched from anywhere with SAO Launcher. It supports 4 functions (+,-,*,/), making it great for simple math like calculating tips without fumbling to find the calculator app. Additionally, it is themeable, just like the rest of SAO Launcher.

The app is designed to work with SAO Launcher and may not work with other launchers. The Play Store forces DRM on paid apps, which messes with the extension code and that is why an in-app purchase is used instead. SAO Calculator Extension is a useful tool for those who frequently need to perform quick calculations on their Android device and want to do so in style.