I have had this phone block for 3 months. It does block a lot of unwanted calls. They block all calls that are not on your contact list. The problem is every two to three days I get 30 to 40 messages from them telling me to contact them with my phone number and name. I have written to them many times with no reply. I will be dropping them shortly because of this. I also found out that my phone carrier is not a big company so they don't screen calls. I have an Android.