I pay $2.99/month to Verizon for the Caller ID Name service. Basically, this gives you the same information that you would get on landline caller id, using the caller name info in the call as sent by the phone network. I would expect that non-service provider caller id apps would attempt to do a reverse lookup of the number, which may or may not be what is provided by the phone network. Whatever. Historically, on cell phones you would only get the caller name if the number was in the phone book on your phone, but that has changed with smart phones.