How about deep diving? It’s not easy and consistent with one app, but it’s pretty satisfying to be the one figuring stuff out.
Or local city planning. Future plans on what to build and where. Doesn’t update as frequently, but it’s something to circle back to on occasion, or you might want to get involved and go to a meeting.
Some people like to listen to police scanners, or alternatively there is usually someone with a social media account who posts just the most important or funniest transmissions from the city/county/whatever
Or you could get an idle game app that you occasionally need to pop into to collect money and upgrade.
Start day trading?
I love it. Order when you’re ready. Don’t have to wait until the waiter is done helping the other table. See additional “substitution” options listed that you wouldn’t have thought of trying. Pay and leave when you’re ready to go