The National Institute for Occupational Safety and Health (NIOSH) is dedicated to ensure the safety of portable ladder users by developing and disseminating an easy-to-use interactive ladder safety application for smart phones. The NIOSH Ladder Safety application features a multimodal indicator, which uses visual, sound, and vibration signals to assist the user in positioning a ladder at an optimal angle. Furthermore, the application provides graphic-oriented interactive reference materials, safety guidelines and checklists for extension and step ladders selection, inspection, accessorizing, and use. The application is intended to help a wide range of ladder users, employers, and safety professionals, with their ladder-related safety needs. The ladder safety app is also 508 compliant.