It holds stuff like:
- A daily journal, plus a curated photo for each day that I can put on a calendar
- Random habits I want to track, like how many cups of coffee I had, did I do my morning stretches, etc.
- Fill-ups and mileage on my car, time to next oil change
- Restaurants I've visited, plus ones I want to visit (I use the Google Places API to search for restaurants)
- Books I've read/want to read
- Movies/TV shows I've watched, and ones I want to watch (I use TMDB to pull in metadata about movies/shows). I also sync my watchlist from Letterboxd
- Strength exercises I do, plus runs + bike rides that I pull in from the Strava API
I used to use several proprietary apps to track these things (Letterboxd, Goodreads, etc), but it's great having them in one place, and with tight control over the database. It's amazing how useful it is to have a log of everything you've done to look back on. Even simple stuff like, last time I was at this restaurant was 2 years ago. What did I order and did I like it?