Truecaller app is one of most needful app for all. With the help of this app you can easily find who calls or texts you.
I impressed with this idea, truecaller sync all contacts of all user and provide info to other user who search for that perticular number and for some number it provides email id and facebook link also so we can find number more reliability.
In earlier day there were some rumours about truecaller like this app hack your facebook, gmail, etc. If you think it will hack your accounts then forget it these are the rumours. Clear your doubts and use it. Must have app in this 21st century.