'Afterwriting is a place where you can play with some screenwriting tools. You can open screenplays written in Fountain format or Final Draft (it will be converted to fountain). You can also use one of the .
There's an offline version too! Just download file, unzip and double click on afterwriting.html.
It's a client-side only app. That means your screenplay is never sent out of your PC.
'Afterwriting is also available as Command Line Interface. More details on GitHub