Truecaller is best app for finding some ones mobile No. you can search Any Phone Number on this app. when you have calling someone that time this app show you this person or company name. You also block unwanted calls & hidden Numbers.
This app also show phone number location. you just login on truecaller via your email id or using fb login after that your add in trucaller family. Truecaller release new messenger true messenger, please download this app on your store. this protects against spam sms. true caller is really best app.