Updates
Run flatpak update as you would for any Flatpak app, or let your software
centre do it:
flatpak --user update
How new versions arrive
FlatPark watches each app’s official releases. Many developers notify FlatPark the moment they publish, and the rest are checked twice a day. A new version is re-pinned, checked to install, and published, usually within minutes to hours of the release; no one has to approve each one.
What you download on update is the developer’s own new release: Flatpak fetches it from their servers and unpacks it on your computer, as it did on install.
Runtimes move together
Every app uses the current version of its runtime (the shared base that
Flatpak apps are built on). When a new version of the runtime comes out, the
whole catalog moves to it at once and is tested together, so you never keep an
old runtime on disk for one app that stayed behind. After such a move,
flatpak update downloads the new runtime once, and
flatpak uninstall --unused removes the old one (cleaning up).