You can absolutely GPS them. Electronic Visit Verification is going into effect in different states. If you are using an app for HH like Timeero to track caregivers mileage, GPS and time, then you will have proof of where they’ve been. Several home health and mobile health companies have been doing it this way.
For travel time and mileage you should look at Timeero. It’s built for home health, nurses and professionals on the go.
To organize your certifications you should check out JobDocs for nurses.
I hope this is helpful