Does Nomorobo really ring your phone once to alert you to what should have been a blocked call?

"If a robocall is blocked, then your phone rings once."

Thank you for the info, KevinM2. That's a deal breaker, free though the software may be. 

yeah i am having the same problem . I get calls all hours from either telemarketers or scammers. Why would we want our cell phone to ring even if it is only once. I'll get 7-10 calls a day sometimes. That is just as aggravating as the calls them selves? Why does norobo work ONLY if you provide another phone number like a cell? Flawed system. Yes the numbers should be blocked but we shouldn't have to have a different phone ring!

Right but my problem is that it is also ringing my cell phone and it continue to ring repeatedly. So; it seems that norobo is not working. My settings say that the land line is setup for norobo by default but,  unless i have the cell number listed as-well then norobo will not save my settings and remains turned OFF. Also when i do add my cell number  both land & Cell phones continue to ring repeatedly, and not just once, until the call ends.

As I was fed up with the daily onslaught of robo and junk calls, as well as providers' inability to stop them, and because we needed new phones anyway, I purchased the AT&T CL82407 DECT 6.0 system of 4 phones and base for $79.99. The system has a Smart Call Blocker built in that requires anyone NOT in your directory or whitelist to press '1' once to get thru. You can then whitelist them. So far it has stopped the phone beggars dead in their tracks. Not a single robocall thus far. And NO one-time ring at all. Problem solved. 

That's a nice feature.  If you have legit robocalls...dentist or doctor reminders for appointments, whitelist them as well.