If you use the Camper Leveler app (Free or Pro), you better use the Wizard.
If you do not want to use the Wizard – or if you use the Caravan Leveler app – follow instruction below on how to calibrate the Leveler apps.
Calibration happens in the app itself. Calibration tells the app what is considered to be flat/horizontal.
This works the same for the Camper and the Caravan Leveler apps.