Ontra Mobility is a platform for planning, integrating, and operating conventional fixed-route services and on-demand services to create on-demand multimodal transit systems. Our platform allows companies to serve more riders, more efficiently by optimizing their network design and leveraging real-time ride-sharing algorithms. We provide white-labeled mobile applications for riders and drivers, as well as a web platform, all of which combined allow transit agencies to improve the efficiency, robustness, and data analysis of their transit system.