NoPhoneSpam - Block calls from annoying or private numbers on your Android device. By bitfire.
Silence: Block Unknown Callers - Block unknown callers. Contribute to x13a/Silence development by creating an account on GitHub.
CallApp - Free Caller ID & Call Blocker app that allows mobile users to block phone calls, identify calls, blacklist unwanted callers and much more.
Truecaller - Find a person by a name or phone number worldwide for free using Truecaller.
Nomorobo - Nomorobo blocks annoying robocalls, telemarketers, and phone scams.
CallStop - Block robocalls and spam using a simple and efficient whitelist