After Canonical announcement that future versions of Ubuntu will not include Flatpak support by default, someone has already created an unofficial Ubuntu flavor that comes with support for Flatpak apps pre-installed and running. The new flavor is called Ubuntu Flatpak Remix.
Ubuntu Flatpak Remix, an unofficial Ubuntu derivative that lacks support for Snap apps but supports Flatpak apps that work out of the box.
Many core apps are pre-installed in Flatpak format rather than Snap format, including the program tourς Mozilla Firefox, the Mozilla Thunderbird email client and the latest office suite LibreOffice.
The connection to the Flathub portal is already done, so you will be able to install more apps in a few clicks.
The developer of Ubuntu Flatpak Remix states that the new flavor was not created out of any kind of grudge against Canonical or the Snap package format, but as a solution for Ubuntu fans who dislike Snaps and prefer Flatpaks.
Those interested can download Ubuntu Flatpak Remix from the official website.