Or, it can be a grave danger to OPSEC, as iPhones (especially) are constantly tracked. Further, all data is imprinted with metadata (data about the data) that includes coordinates, times, etc.
I'd also question the accuracy of such a product at distance... Not only would you have to re-zero every time you went to the range (unless you just keep your phone on your rifle which is pretty useless), but the offset of a big square chunk of **** with the camera lens in the corner is going to cause some major trajectory issues. Not only that, but how much vibration are you going to subject your 300-400-600-dollar iPhone to!?
Bad idea conceived by dumbasses who probably only shoot less than 20rds per year...