Letter to Yourself - Send a physical letter to your future self

Amium - A collaboration app that brings conversation to your files

Future Me - Send an email to your future self

Dropbox Paper Mobile - Organize your team’s knowledge in a single place

Letter to my future self - Letter to my future self is a prominent email scheduling service that gives you the opportunity to create a letter with goals and thoughts for your future self and schedule a date for sending it.

Dropbox Paper - A collaborative document-editing service