V12 Data - V12 Data offers rich data sets with verified addresses and emails for personalized marketing campaigns.
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
Lotame - Make your data actionable, learn about your most valuable customers, improve ROI by targeting the right audience and increase relevance across screens.
WhatsApp - WhatsApp Messenger: More than 1 billion people in over 180 countries use WhatsApp to stay in touch with friends and family, anytime and anywhere.
Google Audience Center - 3 votes and 6 comments so far on Reddit
Signal - Fast, simple & secure messaging. Privacy that fits in your pocket.