Hours of Service within WorkPlan can be used either as an electronic logging device (ELD) to help with ELD compliance or as an automatic on-board reporting device (AOBRD).
Check with your supervisor to find out whether you should use WorkPlan as an ELD or AOBRD.
If your vehicle does not have the appropriate hardware unit installed, the Hours of Service app automatically uses the AOBRD mode, which has less strict regulations and uses GPS to determine driving times.
While you are in AOBRD mode, a red banner is shown in the upper part of the screen:
For more information on AOBRD see this article.