A new split-screen mode is now available which provides added safety and convenience by letting you run another app in parallel. For example, you can let Ultimate Driving Mode handle your calls and messages without disrupting navigation in Google Maps.
Split-screen mode requires Android 7 (Nougat). It will be triggered automatically when you use a navigation command or press your phone's home or recent apps button. It can be turned off at any time in the Miscellaneous section of the settings.