True caller is an app which enables you to use it as caller id, it shows name of all the calls you make or get.It works smoothly and the concepts is very good.About 15 mb app and avaliable on playstore.Not only while calls it has a feature to search the name of the number you wish to search in it.It runs with wifi and internet data connection.it also gives you option to block spam calls.It gives us the feature of call blocking you can add any number to the blocklist.it also shows the email & other info of the person if available.It is very usefull and you can install it to be free from spam calls.