Add flatpak to flathub
@dkardarakos do you want to submit the application to Flathub? The process is relatively straightforward (for ex. https://github.com/flathub/flathub/pull/2326).
You'll need to create a patch for the metadata commit (since you'll need to build from the v21.05 tarball). The other option is to also wait for v21.06.