This is a simple demo of a functional calculator native mobile application. It is written using Codename One, and can be deployed as a native Android, iOS, Windows Phone, J2ME, BlackBerry, Web, Mac, or Windows App. The code is as follows: package com.codename1.demos.calculator; import com.codename1.ui.Button; import com.codename1.ui.Component; import com.codename1.ui.Container; import com