Meta Box Group is an addon for the Meta Box plugin, which allows you to create repeatable groups of custom fields for posts in WordPress. You can use this addon to gather related custom fields into groups, clone and drag-and-drop reorder them.
This addon adds hierarchy to custom fields, e.g. you can create a group and then create sub-fields for that group. It makes your data more structural and with the clone functionality (repeater), you will have a better look of your data.
The addon can be used with other Meta Box addon such as Meta Box Columns to provide better UI for groups and fields.