I've done several of the audits using this app, but I have never done the big one. As far as using the app, I would do these every week, The app is easy to use and very straightforward. The problems arise from finding the correct items. I did several at a grocery store where the items were all together. There was about 50 items and it took me about an hour. I did another one in an "outdoor" store and the items were scattered all over the store and were things I was not familiar with. The store was huge.That one was a terror. I had to make three visits to the store and it took me well over 4 hours. That store is now on my 10 foot pole list.