Today, games not only built up by programmers, but also the mass of data came from users, games need database inside. Setup a cross-platform database was complicated, now, with modern embedded nosql database iBoxDB, as easy as pushing box. It has been used in industry for years, why people like it?
ONE STOP SOLUTION, add the jar to project, from ORM to Cache, all included, from mobiles to servers, all unified.
FAST and EFFICIENT, benchmarks showed it supports 10k users online.
REPLICATION SUPPORT, easier transfer data to different locations.
Example with jMonkeyEngine using gradle
Website for more information