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.
Future Me - Send an email to your future self
Houseparty - Brining empathy to online communication.
Dabble Me - Your own private place to write. A journal/diary to help you remember what's happened in your life.
Messenger Day by Facebook - Share your day in Messenger
Letter to Yourself - Send a physical letter to your future self