Truecaller is the famous app for searching the identity of caller.Most of the people use it to know callers identity.It has more than 2 or 3 billion numbers in it to search.The second thing about it is it blocks spam calls automatically. You have to update spam list on time to time.Also the latest update introduces some new features like you can use truecaller messanger for messages.It also has swiping feature like swipe right to make call and swipe left to send message. It also provides sending money through upi feature. So, This isba ultimate app guys.