Here's a report of the effort involved with making the Subsurface dive log desktop application run on mobile as well. The tl;dr seems to be that
1) it was a lot of work
2) users don't like the result very much
https://lwn.net/Articles/780031/
There's a huge mismatch between how users want to interact with desktop and mobile applications that makes convergence really hard to do effectively in a single codebase.