I have been collecting coins for over forty years. I love CoinSnap and have graded 2000 of my coins with it. It is about 90% accurate. The two places where it has a problem is the one pointed out in this thread. Really bad coins are wildly mis-graded. The other place where grading does not work is where there is a brown stain on the coin. BTW, proper light is really important and can throw off the app. Once you discover how to properly light the coin it is very accurate. One thing that I HATE is that when I export my library, it does not export the "Variety" which is where the mint stamp is stored. This makes it almost useless for keeping track of coins. (Use my own spreadsheet to track them). Also, the pictures of the coins have to be exported one at a time. Conclusion: Great for grading. Crap for keeping track of my coins.