I have this app and it doesn't do a bit of good. It identifies real numbers as probable scammers. And blocking these numbers doesn't help at all, because these people have a way of dialing a number at random. They never use the same number twice. Every time I hit redial on one of these calls, I either get a recording telling me that it's not a working number, or I get a real person who has no idea that a scammer has just been using their number.