Truecaller - Find a person by a name or phone number worldwide for free using Truecaller.
PhoneGenerator.net - Generate random phone numbers for all countries using the mobile phone generator. These numbers are fake, but they are built using the validations of telephone numbers.
FCorp ID Book - ID Book is a handy, easy to use application specially designed to offer users a simple address book.
CallerSmart - CallerSmart is an application that is basically used for the purpose of looking up mystery phone numbers for free.
ThisNumber - ThisNumber helps you find phone numbers for people and businesses!
DU Caller app - DU Caller is the best caller ID app. It helps you identify unknown number and block unwanted calls.