Callblock - The first app to block telemarketers automatically in iOS
Hunter - Find all the email addresses related to a domain
Truecaller - Find a person by a name or phone number worldwide for free using Truecaller.
Mail Dump - Powerful Extensions for email addresses extracting, verifying and finding
SpoofCard - Disguise your Caller ID
Snov.io - More leads. More sales. More revenue.