One Onsite by Lessen is a utility and tools app designed for vendors and technicians to streamline facilities maintenance work orders. The app assists technicians in efficiently completing their daily tasks by providing relevant information on issues, locations, and historical work done.

The app's key features include a guided workflow with simple language for easy understanding, detailed information and photos related to work orders, guidance to the location to be visited, and historical service information. One Onsite also ensures technicians know what information to provide to the back office based on their trade, making the process more efficient and effective.