Here you can find common Flatpak modules that I've been using in the packaging of different Flatpak apps in my flatpaks repo.
These modules are only updated when the relevant application is updated, and most applications I update only when there's
a new runtime release, so don't be surprised if a module is outdated.
If I don't have a use for a module, then it's very possible that it will be removed.
Due to the above, I suggest copying a module into your Flatpak packaging, instead of adding this repo as a git submodule.
Please note that x-checker-data properties are included in most modules for easily updating them with flatpak-external-data-checker.