I was very much pissed off with the unwanted or spam calls that bothers me every time I was in office. But this Truecaller app provided me a sigh of relief.
This app is really useful in blocking the spam calls because when any spam call arrives it displays you the name followed by some info so that you can take action by blocking them.
Some people have a habit of not picking up the unknown numbers. So this app helps when someone changed their number and calling you from another number it displays you the name of that person so that you can pick that call if you know them.
This should be a must have app in your smartphone as per my opinion.