Live Helper Chat has desktop client compatible with
Read more to download it.
Electron desktop app:
https://github.com/LiveHelperChat/electron/releases
Windows client:
Download
MacOS client:
Download
Linux:
https://github.com/LiveHelperChat/livehelperchat/tree/master/lhc_dc_src - You will have to download source code and compile it. QT 4.x is required.