Now that I no longer manage people or large projects this works excellent for me. I use todotxt.net for Windows, I forget what I was using when I used to use macOS, I think just vim. In windows if i'm doing some sort of batch operation I open it with notepad++ (I manage a someday.txt and horizon.txt to keep focused).

The android app is excellent, with quick widget shortcuts to add tasks, including a panel. I very often when browsing reddit, or whatever else, will "share" anything i'm interested in and then process and sort them later. Things without a context are considered my "inbox".

When I add a due date, the due date actually gets entered into my calendar as a reminder (This is EXCELLENT). Since everything is synced, it doesn't matter if I enter this from a text editor or not, the android app sees it and does the entry. I use dropbox for sync for now, which is not ideal, but I can't be bothered at the time to get my workflow setup on my sync app of choice.