When driving with bikes or other equipment on the roof of your car a single moment of forgetfulness could cost you thousands of dollars. Driving into a garage with bikes on the roof will most likely damage your car and destroy your bikes.
"Something on the roof" will help you remember that you have something on the roof.
Using sensors on your phone the app will try to remind you of the stuff on your roof at crucial times when you might have forgotten.
Start the app when going for a drive with stuff attached to the roof, and stop it when you are done.
While driving the app will work in the background as long as you make sure you accept the popups asking for permission to use your location and to send you notifications.
Make sure you test the audio before starting to drive.
Many vehicles will automatically connect to your phone using bluetooth, and audio might be directed through the sound system in your car. This might or might not be audible, so test it before going for a drive.
This app can obviously not guarantee that no accidents will happen, but it can hopefully be a useful tool helping you remember the stuff on your roof.