A somewhat heavier version of SQLite
SQLead is a somewhat-complete implementation of SupportSQLiteDatabase backed by JDBC, so it can be used on a desktop (but cannot be used on any mobile phone).
SQLead is not intended to be a particularly efficient or complete implementation, but merely a mostly functional one. Be aware, however, that it will probably not use the version of SQLite that will be available on the devices your code will eventually run on, so unless you really know what you're doing, you should probably just run your tests on an emulator, or on an actual device.
Partly to be able to test Room DB queries and migrations without having to spin up an emulator, or connect to a device... but given the caveats mentioned above, mostly just for fun. If you're using the Requery SQLite Support Library, however, it may not be so crazy.