I have had the app for about 8 months and I think it didn't work once maybe twice but the last two times I have used it exactly as I have before at stores I have used before it now can't find any record of the transaction. Even with the cash back I am not getting the best prices at all but the station is close to my house so I eat the difference. If it can't find my transaction I am really losing money and that's not worth anything. Use at your own risk. You will never get the best price.