Truecaller app is one the best app for android and ios platform for those who want to know name of unknown number, I am using truecaller from one and half and year, and it is very useful for me for identify unknown numbers, I already recommend almost all my friend for install them, it is very easy to install and create an account, only need mobile number to create its account, and need 3g or 4g connection for it work, I like its feature and function it very easy to understand and use, service quality is also good, the only cons is it is not working in 2g connection.