The JavaScript app (FermCalcJS) runs as a web page in your browser. It is designed mainly for mobile devices, but will run on any operating system in any modern browser. FermCalcJS has identical functionality and mathematics as the Java and Android versions.
Click here to launch the JavaScript app.
FermCalcJS is a single-page app, meaning that it is entirely contained in a single HTML file. Therefore, you can save the file (FermCalcJS.html) to your device and run it when you’re offline.