GlassWire blocks network access of apps, but does not block the app itself from executing on your PC.
For example gramblr.exe may launch on your PC and run there and use the computer resources like your memory or hard disk space, but it will not be able to access the network and use your Internet bandwidth or data.
If you find gramblr.exe on our GlassWire firewall screen, then click its icon on our GlassWire firewall screen, then mouse over the “path” file location, then choose “go to location” are you able to find the file there?
Then go to your Windows task manager (press Ctrl/Alt/Delete and choose the task manager option) and make sure Gramblr.exe is killed (right click on it and choose “end task”), then go back to where you were seeing gramblr.exe on Windows at its file location, then right click it and delete it.
Now empty the trash and reboot. Did that solve it?