Online services such as Whocalled.us and 800notes.com can help to find who a caller is. Online directories such as Anywho.com and 411.com can also be helpful. Installing mobile apps such as Truecaller can also help to identify the caller.
Whocalled.us provides information regarding whether the number is a scam. The site allows the public to post unknown numbers that have contact them. 800notes is a free reverse phone number lookup that let people find out who called. Mobile apps such as Truecaller show the name of the caller almost instantly when the phone rings; they also allow users to search unknown numbers.