So far my research show the following to be most useful, and most recently updated
https://sourceforge.net/projects/italc/
The following one works, but is not updated for a long time
https://thetechnologyteacher.wordpress.com/vncthumbnailviewer/
This one has some poor videos showing how to use it. Looks modern but videos are a distraction
https://sites.google.com/site/dev4webapps/apps/development/vnced