Uninstall Postman and Vysor
If Vysor and Postman are chrome extensions, you should uninstall from chrome menu. Tools->Extensions, find the extension on the list and click uninstall.
In my case I also had the Vysor icon on the main menu, and after uninstalled from chrome extensions it disappears automatically.
sudo apt-get purge postman
If not work:
sudo snap remove postman