Drift Developer Platform - Build bots for marketing & sales
Spark Mail - Spark helps you take your inbox under control. Instantly see what’s important and quickly clean up the rest. Spark for Teams allows you to create, discuss, and share email with your colleagues
Facebook AR Studio - Facebook's developer platform for Augmented Reality
mlist - Email newsletters, outside of the inbox
Arrow iOS - Give life to texts & emojis in AR
TL;DR Email - Send short emails & read emails as fast as you read Facebook