An electronic device including a continuity sensor and electrical circuitry configured to detect and report the continuity state of an article, container or product packaging is disclosed. The continuity sensor includes a first substrate with first and second coils thereon, and a second substrate with a third coil thereon. The first coil has an integrated circuit electrically connected thereto. The first substrate is part of, or is attached or secured to a part of the article, container or packaging. The second substrate is another part of, or is attached or secured to another part of the article, container or packaging. One of the article, container or packaging parts is (re)movable with respect to the other part. The first and second coils have one coupling when the article, container or packaging is closed or sealed, and a different coupling when the article, container or packaging is open or unsealed.