IM building something for writing was initially for my kids but started using it myself for writing so maybe you can give it a try and give me some feedback :)
The idea started with the purpose to get my kids to write daily for 2 minutes to start then every 5 consecutive days they would get an option to to create a story, image and audio with the last 5 write ups, they enjoyed it and so did I, I left have not done much changes since I built it last year but recently my oldest started asking for things so Im back into it, is called writetogrow.app .

You should also try lifelog by @jasonleow

oh right, my bad.

yes they do,

If you call it "buy me a stake" you get my attention :)

For my latest project I was also wondering about this at the beginning, but I ended up using and emoji and moved on to build. :)
I would look into doing something like that to start.

I just started doing this on a x space and is nice, the option to having to pay sounds good because that would force people to actually stick to it.
I think it would be important to have some sort of progress tracker or goal setting or something a long those line where people can see and share that they actually achieved something and not just attended the sessions but at the end was just to avoid paying 😄