Discovered Flatpak last week. It’s making the process of installing applications on CentOS a lot easier. I installed Flatpak, then got GNU Octave from Flathub. Flathub is where you can get apps to run inside Flatpak, without having to look for a version that will run on your specific Linux Distro. I now have GNUOctave installed and running, after several failed attempts before Flatpak.