I don't really know the answer to those questions. But I know SQLite is heavily used in almost every ecosystem so I would be really surprised if there were real blockers.
I know Android uses it a lot, so I opened up an Android project at my company and it looks like the android SDK comes with a bunch of SQLite abstractions, and it's not clear what the underlying driver is. But the SQLite official website ships an Android AAR so maybe that is it? (https://www.sqlite.org/2020/sqlite-android-3310100.aar)
This seems to be the main general-purpose JVM lib: https://github.com/xerial/sqlite-jdbc and it seems to be keeping in lockstep with the official SQLite versions (within a couple months).
Edit: Also can you elaborate on the "in a multiplatform way"? Maybe I'm having a brain-fart or memory-hole but shouldn't you not have to worry about that at all?
Edit2: Looks like there is a nice blurb in the docs on that github page:
Since sqlite-jdbc-3.6.19, the natively compiled SQLite engines will be used for the following operating systems:
Windows (Windows, x86 architecture, x86_64)
Mac OS X x86_64 (Support for SnowLeopard (i386) has been deprecated)
Linux x86, x86_64, arm (v5, v6, v7 and for android), ppc64
In the other OSs not listed above, the pure-java SQLite is used. (Applies to versions before 3.7.15)
If you want to use the native library for your OS, [build the source from scratch.