shared_preferences doesn't seem to be persisting the download directory setting on Linux. The package page on pub.dev suggests it shouldn't be used for storing critical data, so I guess it's not meant to be very reliable? Also, a minor issue is that using it means that settings would be stored in the wrong place on Linux, XDG_DATA_HOME instead of XDG_CONFIG_HOME as the 'XDG Base Directory Specification' dictates (https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html).

Since PPM only seems to support desktop platforms at the moment ( although I could be wrong about this ), I could write a wrapper which uses the correct directory, based on the Rust directories crate, which I've already written a Kotlin version of. If PPM does support mobile, then I would probably suggest just manually storing stuff in the write place on Linux, and using shared_preferences ( or some alternative ) on other platforms.

The application ID is currently set to com.example.past_paper_master, at least on Linux. It should probably be set to something like dev.scie.PastPaperMaster, or com.github.micfong_z.PastPaperMaster, as explained here.

Currently, the UI renders like this on Android:

The app should probably use a Material NavigationBar for navigation, but I think the rest of the app should? be fine.