I'm keen to use MongoMobile on IoT Edge devices e.g. RaspberryPi - a Java (rather than Android Java package) SDK would be great for that. Is that on the roadmap?
Now that we have MongoDB Mobile GA, we are pivoting a bit to focus more on IoT and Edge devices. Within that space, Debian is #1, with Raspbian being a Debian variant for Pi's, as Pi's have no BIOS. So, yes, I would like to see official Debian (likely 10) support at some point.
But today, you could use MongoDB Mobile directly using the Java Embedded Driver. For an example: https://github.com/mattlord/mongo-embedded-sample_java
You would just need to have a native build of the MongoDB Embedded database available for the Java driver to link in via JNI. If you're using Raspian 9/stretch, then you can use the tar I made here in this project: https://github.com/mattlord/mongo-embedded-sample
You can also see how I built the tar in that project if you want to do that part as well: https://github.com/mattlord/mongo-embedded-sample/blob/master/build-instructions.md
You should also be able to use the MongoDB Stitch SDK for Android/Java, but it won't work "out of the box" because it doesn't bundle the MongoDB Embedded database libraries for Raspbian. You would need to place the same MongoDB Embedded libraries noted above in the default Java JNI path, or specify the location explicitly using java.library.path.
Feel free to reach out to me directly (firstname.lastname@example.org) if you get stuck or have questions.
Thank you for your interest in MongoDB Mobile!