Binary Factory creates flatpak: https://binary-factory.kde.org/job/Labplot2_x86_64_flatpak/
Labplot2_x86_64_flatpak puts package to http://distribute.kde.org/flatpak-apps-testing/

LP is now on https://github.com/flathub/org.kde.labplot2 master (stable) (the beta branch is also used).
Statistics @ https://klausenbusk.github.io/flathub-stats/
Buildservice @ https://flathub.org/builds/

validate appdata:

• flatpak install flathub org.freedesktop.appstream-glib
• flatpak run org.freedesktop.appstream-glib validate org.kde.labplot2.appdata.xml

validate desktop file:

• desktop-file-validate ./src/org.kde.labplot2.desktop

Docu:

• https://community.kde.org/Guidelines_and_HOWTOs/Flatpak
• https://github.com/flathub/flathub/blob/master/CONTRIBUTING.md
• https://docs.flatpak.org/de/latest
• https://github.com/flathub/flathub/wiki/App-Maintenance

KDE github flatpak:

• https://github.com/KDE/flatpak-kde-applications
• https://invent.kde.org/packaging/flatpak-kde-applications/

DONE:

• Add dependency to manifest on Binary Factory and check build/package set INSTALL_ROOT (not to /app though: https://github.com/flatpak/flatpak-builder/issues/228)
• Upload manifest to Flathub (stable version 2.8.1)