Self-plug: I've been working on a similar outline app for about 3 years now: https://zetabee.com/text/ https://zetabee.com/text/ I made it because I was doing

Self-plug: I've been working on a similar outline app for about 3 years now: https://zetabee.com/text/ https://zetabee.com/text/ I made it because I was doing something very similar in my text editor all the time, especially with collapsing/expanding sub-lists. It has pretty decent keyboard support and very few unnecessary features. I was going to build a 'check' completed feature but I've realized I just don't care about things I've already done. I only care about what's next. So Control+Del to delete a line is enough. It is a slightly opinionated app but being mostly plain-text with indents, you can use it however you want. I don't plan on making money with it and it has near zero operating cost. So it's free/secure/unlimited and will remain so forever.