When telemarketers completely ignore the fact that your number is on the National Do Not Call Registry, this app steps in to help put an end to RoboCalls. They call it an intelligent call management app with loads of features, but the one I like the most is: when you get a call from an unrecognized or blocked number, it sends the tell-tale tones and announcement that “this number is no longer in service”. The outgoing message even has the static and crackle that you can hear when you actually reach a disconnected number.
I got the app just for this feature...but it has more. Essentially, YouMail is a replacement for your voicemail and acts as your virtual, personal assistant. It offers customized out-going messages for friends on your contact list (“hi, Dan, Jason can't take your call, but I'll make sure he gets the message”), it will convert your voice mails to texts and send them to you that way, call forwarding for important calls and more.