Finally a really simple way to permanently, or temporarily block Unknown and Private numbers.
Goodbye Mr PPI merchant, Accident lawyer and others who hide their phone number because they know you do not want their calls.
Runs as a service , when enabled settings will survive a reboot and carry until you disable blocking.
How to disable it? Use the notification icon or app icon and press the toggle button.
Designed for Android 4.1 +
Tested on Nexus 6 - Marshmallow and Galaxy S3 - Lollipop
Device reports welcome