A gnome-shell extension to show 'Activate GNOME' watermark. Migrating from Windows has never been easier!
git clone https://github.com/isjerryxiao/gnome-shell-extension-activate-gnome activate_gnome
make -C activate_gnome
ln -s $(realpath activate_gnome/activate_gnome@isjerryxiao) ~/.local/share/gnome-shell/extensions/
Check this out.