I was using nomorobo. It worked well a few years ago but the last year or so it's been a waste of money. You Mail worked from the first week I loaded it. My phone hardly rings unless it’s a human. Can you hear that? That’s the sound of silence! Thanks You Mail!
You can tell these guys put a lot of time into developing this app! Has lots of great features and I definitely would recommend that you try it out. Have Sprint and are tired of "unknown" or "unavailable" calls with no way to block these types of incoming calls? This is the app for you. This sole reason I got it and I am more than pleased thus far.
It is free and then ask u to subscribe for better features. But free is good enough for me and adequate. And it is fun at the same time.