I have been using the Android App “Call Detector” by First Orion. Unfortunately it does not work. I still get calls everyday and it does not stop them. They don’t ring but you can shut off the ringer on calls that are not in your contact list. So, it does not do anything worthwhile. It does not stop the call and every day I receive calls from a company in India that uses a different US telephone number and does a robocall and they leave a voice message. Wish Call Detector would have worked I use a Tracfone.