How to unmask no caller id? (UK)?

My daughter is getting threats from no caller id's on her iphone, it is jailbroken and we can't find a website or tweak that can be used in the UK

I would greatly appreciate if you could recommend some sites or jailbreak tweaks to help us unmask this no caller id so we can send the number to the police

Report it to the police and they can get the number traced out.

  • Which app can I use to call and change the caller ID? I've seen my friend use this app that he calls but he can change the caller ID, I remember he called someone and he put 911 as the caller ID. I would like to know what is the name of that app for the Apple Store / iPhone / iTouch.
  • What's the difference between an 'unkown' caller and 'no caller ID'? This unknown number keeps ringing me, and i thought if someone blocked their numbers (on iphones) it comes up as no caller ID so i'm not sure if it is still a blocked number or a number that can't come trhough. But when i answer nobody speaks and they've rang one of my friends so its not a scam phone call also they don't speak at all so if it was a company of some sort they must of spoken so its probably a prank call but i wanna know the difference to make sure.
  • Is there a free caller ID app to allow you to see names? Someone told me there's a Iphone app to allow you to see the name of the person calling. At this point my Iphone only shows the number unless of course they are in my contacts. I'd like to see the names of people if there's a app for it.
  • Is there a caller block app for iPhone? So this guy keeps calling me and texting me and I wanna block him but when I looked online it says my phone has to be jail broken to do it but is there any other way because I'm just getting annoyed because I told the guy I'm not interested and he want leave me alone.