"Old school" foragers typically stick to a few mushrooms to be safe. Meaning, they have quite an expertise on 3 or 4 kinds of mushrooms (or, even more likely, just a couple of them) and are staying away from anything else, especially, if there is a similar, poisonous mushroom. (At least, this is what all I happen to know are doing.) Also, if you aren't 100% confident, stay away from it. (And there is the real problem with apps, since lack of confidence is the entire raison d'être of these apps.)