I was in the parks for 12-13 hours today. I used my app for maxpass (pretty heavily), mobile ordering once, checking show times/wait times and entering (but not saving) ride photos. I used 263 MB. Seems too high, but that is what my iPhone is telling me since I reset the stats around 10am.
That seems like a lot. I will have to make sure I reset mine on Sunday before going. I practically live in the app while in the park.