Download USMON Chat for Windows
(the preferred version)

Note: This will require Java to be installed.
If you do not have the latest Jave software,
you may download it for free.
Download Java 8 for Windows

If you are running an NON-PC product (such as Mac, tablet, etc.), you may try the web version of USMONChat.
Note: We can not guarantee that all features will work as they do on a Windows PC platform due to operating system differences.
Use at your own risk. USMONChat Web Version

For Screen sharing, ScreenConnect recommends that if you are using a Window's PC computer that is NOT on Windows 10, you should make sure your .NET software is up to date.
ScreenConnect is based on .NET code. You may download this from Microsoft at (if your PC is NOT on Windows 10):