By Melanie Trottman

The National Labor Relations Board is marking Labor Day with a mobile-phone app to inform workers, employers and unions about their rights under the decades-old labor law.

“The promise of the law can only be fulfilled when employers and employees understand their rights and obligations,” NLRB Chairman Mark Pearce said in a statement.  The agency received more than 82,000 public inquiries last year about workplace issues, and “this app can help provide the answers,” he said.