Flatpak

flatpak remote-add flathub https://flathub.org/repo/flathub.flatpakrepo
flatpak remote-add --from gnome https://sdk.gnome.org/gnome.flatpakrepo
flatpak install flathub com.slack.Slack
flatpak install flathub com.spotify.Client
flatpak install --from https://firefox-flatpak.mojefedora.cz/org.mozilla.FirefoxDevEdition.flatpakref