Future Me - Send an email to your future self
Letter from You - Handwritten letter, mailed for you in the future.
Letter to Yourself - Send a physical letter to your future self
Dabble Me - Your own private place to write. A journal/diary to help you remember what's happened in your life.
Little Memory - memories for your future self what do you want to remember about today?
Futurospective - An app that let's you record messages to your future self