Show Gradience, Flatseal, Loupe Image Viewer, and Resources running on Ubuntu 16.04

Show Firefox 118.0.2 running on Ubuntu 16.04

Show Door Knocker, Collision, and Cartridges running on Ubuntu 16.04

Show ASHPD Demo running on Ubuntu 16.04, showing a notification through XDG portals

According to Door Knocker, almost half of the portals are unavailable on Ubuntu 16.04, compared to only one unavailable on Fedora 39 with GNOME, which means Flatpaks running here may have more limited capabilities than usual.