Login Manager Settings or gdm-settings is a new app developed by Mazhar Hussain that lets you change various settings of GNOME‘s Display Manager (a.k.a. GDM). Under the hood, the application is written in Python, but its graphical interface is written using GTK4 and libadwaita to provide users with a modern UX.
The app features no less than seven panes with various settings including the ability to change shell, icon, and mouse cursor themes, as well as to change the background to an image or a solid color from the Appearance pane.