Check out Mr. Number. Ive used it on Blackberry, Android and Apple. It uses a online database to auto block calls from telemarketers, known scams, collection agencies, plus you can block whoever you want ofcourse. I know on android and blackberry it could block texts too. I havent messed with that on apple yet.
haha I guess my mr. number days are over, seems its neutered on iOS. Cant block calls. move along... lol