Reading through the comments under this thread, there are many users who swear by a plain text file, but who then build quite a lot of snowflake software to regain functionality offered by more structured TODO applications. That includes: - having your computer alert you to things that come up - being able to tag notes - being able to add events to a calendar - being able to set priority of tasks - expecting prioriti…
If my own experience is a valid example, alerts are overrated. They don't work for long. I hate getting interrupted by something that actually does not need my attention at that precise moment. I would disable those alerts in no time.
I prefer leaving physical cues in the real world. I think screens are bad UI unless you already spend way too much time in front of them.
The god old in- and out- baskets are great, for example. Or notes on a physical board.
Sometimes when I think of something I want to do in the morning, I just leave an object that does not belong in a place I will definitely have to use in the morning. Seeing that object will remind me of that thought I had just before going to bed. I don't even need to write down what it was.
Physical cues are wonderful! And THAT is what I would want from Augmented Reality (in addition to it no longer requiring cumbersome hardware to wear). A flexible recreation of former physical work places, but using the new flexibility of computer augmentation of what I see. To be able to place digital notes in the real world. To view and touch documents not fixed in a single place in front of me, but anywhere! I put some documents on the left, some on the right, some on the wall, and I move my body around to view and use them.
A purely screen-based app, when I already hate having to stare straight ahead for hours every day just doesn't cut it for me. I want my digital world to be in the real world, and use my entire body, not just very limited arm and hand movements while barely moving the head because the viewport is just one small two-dimensional rectangle in my large reality.
Okay, that went slightly OT, but I made that point because it is relevant for TODOs and most interactions with computers. I think they are much better when tied to our real world, not inside a tiny screen where a lot of stuff is already squeezed in and waiting for our attention, and everything can only be used like a surgeon doing keyhole surgery - indirectly through a tiny port and tools, instead of ones hands. Place TODO hints in the real world on or near appropriate places.