I have been using Truecaller app in my android phone for quite some time.This is one of the most useful apps after whatsapp and shazam.Whoever made it, kudos! You guys are gold! Obviously this app works with an internet connected phone.This software detects almost all calls to my phone from unknown numbers and neatly presents caller name and location on top of my caller app.If the number is spam, it will be shown in red so that we can easily block the number.Specially good app for ladies .
During this time, I have blocked around 25 unwanted calls and spam calls using truecaller.
Thank you, truecaller!