The two options I've used was using a smartphone app or adding another odometer. The 2-3 smartphone apps I used can pull too much phone battery power and data when it is always updating your position. I even connected my iPhone to the usb port on the LCD and the app would still pulled a lot of power just to maintain a steady power level. In the end, it was too much trouble to use the app and connect to usb port in extreme weather (below freezing, +100 degree days, dusty trail rides, rain).
The second way was attach a wired or wireless odometer to the ebike. My 16 Radrover odo stopped updating trip data (total miles, trip data, current mph); but, it still displayed PAS level, wattage levels, back lights, and set-up screen functions. I added a wired odo to the front tire with a back light that is USB rechargeable. Lots of inexpensive choices out there that have a lot of features.