I only knew how to make web apps, so I did what I knew, and built a web app. I used React on the front end, and Python Flask + AWS Lambda on the back-end.
It worked and increased my engagement by over 10x immediately. However the usability of the web app was not ideal. I felt that it should really be a mobile app.
The problem was that not only had I never made a mobile app before, but my laptop was not powerful enough to support an app development workflow that would keep me sane (4GB RAM). And it was Windows, so had issues running the required libraries.