Truecaller - Find a person by a name or phone number worldwide for free using Truecaller.

Callblock - The first app to block telemarketers automatically in iOS

You've Got Spam - A new tool that lets you spam back the spammer

Callwarden - Go to war on spam calls 📵

SpoofCard - Disguise your Caller ID

RoboKiller - A paid application for iOS and Android users which blocks and pranks spam callers, such as scammers.