Cotter - One-click phone number login and checkout
Callblock - The first app to block telemarketers automatically in iOS
Feather Auth - Build an entire sign-in flow in 5 minutes or less.
Truecaller - Find a person by a name or phone number worldwide for free using Truecaller.
Authpack - Complete user auth system installed with 8 lines of code.
SpoofCard - Disguise your Caller ID