With the upcoming Flatpak 1.2 release for app sandboxing, the command-line experience will be much better for those that prefer the CLI to the graphical utilities around Flatpaks.

Red Hat's Matthias Clasen has outlined some of the CLI improvements they have been making for Flatpak 1.2. Some of the improvements include better presenting information in a tabular form, more concise error reporting, friendlier searching of packages, utilizing AppStream data to present more information to the user, and indicating progress on the installation/updates of Flatpaks.

Flatpak 1.2 is expected for release in early 2019 and more details (and screenshots!) on these command-line interface improvements can be found via Clasen's blog.