Truecaller where you can get the information about the unknown caller, which have some name listed in someone’s phonebook or else. So its a good app to know that unknown who is caller.
But the problem is that, I have I phone , I download from the app store , & start using the worst thing is that you need to copy the number you want to known who is truecaller than paste it to the truecaller search option, which is not the good thing, It runs very well in androd phones because you dont need to copy or paste becoz when some unknown calls you , u can get their no.detail ( who is truecaller) in your screen when in incoming call. So so good for iphone user .