They are enabled to (also) run on phones.
E.g. libadwaita makes it possible to write application which can adapt to the screen size and therefore run on big and small screens.
Yes, they are mine. I guess the question is targeted if they are done on a mobile device. The screenshots are done on Fedora Silverblue Gnome on a Dell XPS 13 laptop developer version (~7 years old).
But I also have the Librem 5.
You can put the newer apps in a 'simulate phone screen' mode (it's still in development).