Flatpak synching between machines

Currently, it’s rather bothersome to sync the Flatpak packages installed on multiple systems: One either has to manually keep them in sync or use the CLI to get a list of installed Flatpaks. As such, it would be useful to have an application that can do this for users. The go-to approach would be a D-Bus daemon that automatically (either on changes or periodically) creates a list of installed Flatpaks and pushes it to a service like GitHub Gists. If a new version is detected (which comes from a different system), the daemon would fetch it and adjust the local installation accordingly. Additionally, there should be a GUI application that can interface with the daemon for setup and configuration. A CLI application for usage independent of the DE and manual syncing would be a plus.