SaaSiter Contacts Importer - Allow users to import contacts into their system.
AddThis - AddThis free website tools include share buttons, targeting tools and content recommendations help you get more likes, shares and followers and keep them coming back.
OpenInviter - OpenInviter is a free import contacts (addressbook) script from email providers like Mail2World...
Buffer - Buffer makes it super easy to share any page you're reading. Keep your Buffer topped up and we automagically share them for you through the day.
CloudSponge - Companies from every industry use CloudSponge’s Contact Picker to get access to their users’ address books.
AddToAny - Share buttons by AddToAny, the universal sharing platform for websites and apps.