I've recently built a fully functional web app which I was able to get up and running on a cloud server, and then successfully embed onto my company's website. However, when viewing the application on a mobile device, the user interface looks poorly designed in contrast with the desktop version, and some of the functionality is lost.

My guess is that these limitations on the mobile side stem from the fact that I've embedded the web-app as a single HTML object/widget. I've read some literature and blog-posts about using flutter and shinyMobile to transform the web app into a mobile version, however at this point that's not a feasible remedy for me (due to lack of knowledge in that area and lack of time I can devote to learning it). I've also been using the devtools to look at how the app behaves when the user engages with it, however I'm not well-versed on how a 'web manifest' works.

Hence I was wondering if anybody had suggestions on how I can configure the appearance of the shiny app on a mobile device? Ideally a solution that does not involve extensive knowledge of JS or languages other than R and HTML/CSS.

Please let me know if you need any clarification or additional information.

Cheers