I've been working on an app that allows me to send messages to my past and future selves, as well as posting today's thoughts (for reading by my future self). I had initially created it over a weekend as a fun side project, but it turned out to be a great tool for self reflection. An ios beta is coming out next week, fill out this form if you'd like to try it out: https://forms.gle/C9KebsV2u64Wqvc56
How do you manage to send messages to your past selves?
I use the schedule future email feature in Gmail it's nice to reflect on in the future my current fears/concerns at that time, am I still alive, etc...