flatpak-run
Run flatpak applications and runtimes.
TLDR
Run an installed application
$ flatpak run [com.example.app]
Run an installed application from a specific branch e.g. stable, beta, master
$ flatpak run --branch=[stable|beta|master|...] [com.example.app]
Run an interactive shell inside a flatpak
$ flatpak run --command=[sh] [com.example.app]