In 2019 I made a fairly simple app that sends me an email everyday that I just need to respond to and the text of the reply gets added to a database. I have almost never missed a day since Oct. of 2019.

Some observations:

- it can be pretty hard to remember a mundane and ordinary day just 24 hours later, and after 48 hours it's usually completely gone from memory

- important or unusual events (or parties!) stay in memory a little longer

- and for me at least, food is an excellent memory anchor; if I feel lazy and don't want to add to my journal, just noting what I had for lunch and dinner will help me remembering the rest of the day much better later.

Had a similar idea focused on old pictures. Think of older family members going through a box of photos and explaining who, when, where, etc...