Deskreen – Turn any device with a web browser to a second computer screen
You don't need Deskreen, you can extend your Windows desktop to a second screen on any device easily by using: Zonescreen (https://zoneos.com/zonescreen/) or TightVNC with DFMirage Driver (https://www.tightvnc.com/download.php). For an in-browser VNC client there are: noVNC (https://novnc.com/) or Apache Guacamole (https://guacamole.apache.org/) or ThinVNC (https://sourceforge.net/projects/thinvnc/). As you can see, there are already many solutions for this use case. I also have made a VNC-like remote screen using Kindle 3 (https://github.com/niutech/kindle-vnc).