I would advice testing this idea on iOS only, find PMF, find SEO patterns, then consider expand. It also depends what framework you are using to build the app,

I would advice testing this idea on iOS only, find PMF, find SEO patterns, then consider expand. It also depends what framework you are using to build the app, cross platform vs native. It is not worth maintaining two platforms in the beginning, not just dev efforts, QA efforts, but just understanding how these two platform works would consume lot of your time.