How many of the people who use these gun log applications are the same people who spend countless hours blacking out the serial numbers of their guns when they post a picture of them on the internet?
Its stupid, ludricrious moronic to put a list of your weapons onto a device thats very popular for theives to take. when the phones get taken the theives go through it looking for your "convenient' banking applications to get your banking/credit card data so they can go buy the yacht theyve always wanted.
and anything labelled "gun log" would always be stolen. and when they realize you got a musueam of all weapons ww2, they will come do a stop and rob on your house, and then if you put in the names of the people you got anything from, or sold to, those people would be next.
its like giving a pedophile a lsit of all the young children in your neighborhoods with names and photos and addresses and when theyll be home alone.
They might just do what you describe. Other factors, such as where you live, might mitigate the problem. Another possible outcome is that after they look at all the data on your phone they decide not to come to your house because they might just get greeted by the muzzle of gun. Who's to say what someone else might do. But I do understand the concern.
My father-in-law had his gun and coin collection stolen. Guess who did it! Youngest daughter's boy friend. (I did not marry the youngest daughter! It wasn't me.)