Gridbuilder ᵂᴾ comes with an exporter that allows to export in .json format your grids, facets and cards. In that way you can easily save/backup your current data and import them into another site thanks to the importer.
The built-in importer allows to import .json files generated from the exporter tool of Gridbuilder ᵂᴾ. The importer also comes with all card demos of the plugin. So, you will be able to re-import card(s) at any time.