Any food item that has a bar code label is also going to have a list of ingredients. As the ingredients in a manufactured food item may change from time to time, the manufacturer of that food item is required by law to change the list of ingredients on the item. But they are NOT required to contact the makers of this software and advise them of the change.
So, if you place your confidence in this sort of thing, you expose yourself to the danger that a formerly GF item, listed in the software as safe, might actually be unsafe because the ingredients have changed.
The only way to protect yourself against an outdated version of this software is to read the ingredients on the package and make your own determination of whether or not the item is GF.
Manufacturers of prepared foods also introduce new items all the time. What about the case of an item that did not exist yet when a version of this software was created? The software will not know if the item is GF, and you will have to read the label.
If you are still going to have to read the ingredients anyway, which is what I'd suggest, then all that the software does is make it take longer to do your shopping.
Would a person using this software avoid buying foods that do not have bar code labels? Usually produce and other fresh food items are sold loose, without any kind of a bar code. It certainly would be a shame if a person using this software ended up avoiding the food items that have no barcode, as those are likely to be the ones that are most nutritious and also unequivocally gluten free. A head of cauliflower is always going to be GF, same for peaches and strawberries.
I think it is a really bad idea. It reinforces being dependent on others for your health care. I prefer to read the label myself instead of being dependent on someone else to tell me what is and is not safe.
