Sync status indicator for the third-party google drive client insync for gnome-shell
Clone this extension into your extensions folder:
cd ~/.local/share/gnome-shell/extensions/
git clone https://github.com/oweissbarth/insyncindicator.git insyncindicator@mail.oweissbarth.de
Then enable the extension using gnome-tweak-tools or through the commandline by running:
gnome-shell-extension-tool -e insyncindicator