I use the Tasks app and have for years... technically I keep a bullet journal too, but I'm not consistent with it at all... the organizational structure of Tasks just works so well for my brain... we are all different, but I hope if you feel like trying it, it ends up being useful for you too

I just looked it up, and unfortunately it isn't FOSS :( - it's free to download but getting the sourcecode is against their terms of service

Okay, now that I've thought fora minute, we use Kanboard, which also has a kandroid app between @silverwizard and I...

It is not nearly as intuitive and I don’t like it as much but it's FOSS and you have more control over the features, but the nicest feature (for me) is being able to auto populate the task again in x amount of time from either when you close the task or when it's due....

Not as easy or intuitive but if you're doing your own thing might be worth a shot?

My experience is that you want a very limited checklist apps with a checklist that you can easily make into text messages and check off. Whereas Kanboard is very heavy - but fairly easy for sharing, but requires a server.

There's a bunch of very lightweight things similar to Tasks in F-Droid but you don't have the open-source purity desire to test them. And you don't feel the need to sync to a laptop, since you use your laptop like once a month.

I have a hard time articulating what I like about tasks, and I found something that works and so it's stressful to search more, but absolutely you're right that I don’t have the open-source purity to go on a dive, which is something that I don’t really like about myself, but that's another topic

I guess I'll do my best to articulate in case it's useful to anyone else

Tasks
-I like that it doesn't delete tasks immediately when they're crossed off and when you do delete an item on accident, it's easy to get it back
-I like that you can text a list easily and simply to another person
-I like that it's got sections, and sections within sections, and sections within that if you need them and everything is colour coded with a lot of colour options
-I like that it shows you a list that shrinks nicely or shows up all the items that you've completed as crossed off, depending on the mood
-If you can autopopulate, I haven't figured it out, that does suck, that's my favourite feature of kanboard

Kanboard
-I like that you can autopopulate tasks
-I like that you can create different columns based on the task list which you can have for varying levels of completeness or urgency
-I like that it's opensource and it's easy enough to use
-Once a task is complete it's closed and gone, so that's probably my least favourite thing, but not a dealbreaker either

There might be more, I'm not entirely sure. I hope that helps with decision making