I see there is an "android" Java/Kotlin interface. Is there one just for plain old standard Java? Alternatively, is the source for the Android library available (I was going to take a look to see how hard it would be to de-Androidify)?

The Java version is mostly finished. We haven't written documentation yet, but I think it's published on Maven central already. It shares the same code base as the Android SDK - https://github.com/growthbook/growthbook-kotlin

Thanks! For some reason I can't figure out, while I can add

implementation 'io.growthbook.sdk:GrowthBook-jvm:1.1.1'

to my build.gradle, and it gets downloaded, I then don't seem to be able to import it -- I might be doing something very silly, but (famous last words) I'm using several other libraries correctly. A complete demo using this would be useful (I imagine such a thing will come in time!)