Hinge - Find people you want to date through your friends on Facebook.
Missive - Team communication app now supporting FB, Twitter & SMS
Quip Chat Rooms - Real-time chat with your team
Spike - Spike solves businesses' communication chaos by bringing together email, team chat, collaborative docs, and meetings, into one feed.
Slack for Mobile - Rebuilt from the ground up
Mailtrim - Email lives forever!. Reinvigorate your emailing experience with the best free email client, the Mailtrim