I built a personal finance app using RN - https://www.titmiceapp.com/. I had some prior React.js knowledge but rest assured as long as you have javascript experience, you can do without it.

The biggest pain point so far is adding analytics but otherwise, everything is pretty smooth sailing.

Also I come from a web developer background, so structuring layout isn't too unfamiliar. AMA if you have any qns. I'm looking to pour all these experiences into a blog post before my next distraction comes and terrorizes my short-term memories