Wait, this definitely exists, I just can't remember the exact name of the app. I used it to detect Nestlé products (turns out way more things than I could imagine belong ti them). But basically you tell it things you support and things you are against. Then when you scan a barcode it tells you if it is aligned with your stance. Trying to find the app now, it was called Buycott, but it doesnt seem to show in the store,probably changed names