Future Me - Send an email to your future self
Grove - Personalized financial planning for everyone
Letter to Yourself - Send a physical letter to your future self
Betterment - We manage your investments so you don't have to.
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.
Inbox Creature - A super cute virtual pet, delivered right to your inbox.