The Ruffle addon lets you run Flash games safely in your browser. Until now, there was no virtual keyboard that lets you play games on mobile. I made a simple userscript to display a virtual keyboard with arrow keys and spacebar. It uses focus, dispatchEvent and KeyboardEvent to communicate with the Ruffle container. You can download the userscript with Tampermonkey and try it out: https://github.com/ed253/ruffle-virtual-keyboard