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!!
In linux Mint 19.0 (flatpak v. 1.0.9). Simply doesn't launch.
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.