Long Mobile Form times out and erases data

I am using a form on the mobile app that has approx. 100 fields that takes someone an hour to fill out sometimes with 5-10 minute pauses in between filling fields. It is for a multiple building property inspection so they have to drive a golf cart between buildings to check the different things that are asked in the form fields. The problem I have is that if they wait too long in between filling fields, the app (and the link via safari or google) will reset and they will lose all the data filled in so far. Does anyone have any work arounds or ideas? I have had to resort to printing the form, they fill it in manually, then they come back to the office and enter it into the app after the inspection is done.