To get any Linux app running on Umbrel install it from the Firefox app, once in Firefox close or resize the window to see the black background and with a left click open the launcher menu, it will show Firefox and Xterm, open xterm and your ready to install anything from the terminal too or other apps downloaded from Firefox at this Alpine linux container as long as the packages are in APK format (not android) or Appimage apps – AppImages. most DEB or RPM packages can also be converted but it would take extra steps.
To add more shortcuts to the Openbox/Busybox launcher menu you can modify the file:
/config/.config/openbox/menu.xml
to apply the changes just run:
openbox --restart
It’s not a native way to install apps since everything would be under Firefox, but it works within a nice remote viewer with file transfer and clipboard support.
To suggest new apps natively supported I guess there’s another post:
https://community.umbrel.com/t/what-apps-would-you-like-to-be-added-to-the-umbrel-app-store/235