Launched Todowing: a userscript I ran for months, validated on reddit, now a paid extension

I've been a Todoist user for years and rely heavily on checklists and daily routines, but Todoist hides sub-tasks in the Today, Upcoming, and filter views. Opening every task just to see its checklist got old years ago, so I spent a day poking at the API and built a rough browser extension that showed them inline in my Today view.

I ran it myself for months. Before cleaning it up for release, I posted on r/todoist asking if anyone else wanted it and what else bugged them about the web UI. The response convinced me it was worth releasing properly, and the thread gave me a ranked feature backlog for free.

So now it's live: https://todowing.com. Sub-tasks show up inline under their parent, up to 4 levels deep, with checkboxes right in the list.

Decisions I made and why:

- One-time $9.99 instead of a subscription. It's a UI enhancement with no server costs (everything runs client-side), and I think charging monthly for that erodes trust. All future updates included.

- Free tier caps visible sub-task rows at 5 per task instead of time-limiting a trial. You keep the value forever on small tasks and hit the wall exactly when the extension is most useful to you.

- Web-only, honestly stated on the landing page. It runs on Todoist's web app; the desktop and mobile apps can't load extensions. I'd rather set that expectation up front than deal with refunds.

Next up: font and font size support, then whatever the feedback pushes to the top.

If you've built on top of someone else's app, I'd like to hear how you handled the platform risk. That's the part of this that keeps me thinking.