UPDATE: Previously, in Mint 21.3 XFCE, Flatpak apps installed OK but their desktop launcher icons would not start them (launcher icons made using "Add to Desktop" in the Application Menu, which was the Xfce4-whiskermenu-plugin V 2.7). That was fixed by upgrading the whiskermenu plugin to V 2.8.3. As before, Flatpak apps can be started directly from the Apps Menu, or by using the Desktop's "Create launcher" tool. The latter method may be a bit obscure to users new to Linux Mint. Still, it's too bad that Flatpak packages have to be so huge.
Paks are large and slow. Slow to install, unbearable to open. I avoid ubuntu because of snap and here I find paks here. Stop forcing this "new" way of distributing software down peoples throats. I would prefer apt or even compiling from tar than give up that much control and access to my system. Should not be auto installed
From installing an app to running one, I can always tell when it's Flatpak'ed, because it's slow and painful. If I see a flatpak app, I look for an alternative anymore. AppImage is so much better.
Note to other "reviewers": this is a *framework* not an application to run. As it is, it works perfectly fine on Mint 19.3. I have successfully installed and used flatpak'ed applications with it. So, it does exactly as it says on the tin, hence 5*.
I've spent the last 3 days trying to make flatpak work in L.M. 19.3. So far, none of the apps open up. Something has gone wrong in the installation process, and it sucks!!
Doesn't work for me. Starting a flatpak app, immediately results in a crash in Flatpack. Installation of a newer version of Flatpak (0.10.2.1.) didn't help.