Nocturnal has just released Catapult v1.41.4. This release includes full compression support for GBA ROMs, including ADPCM compression for sounds - and support for a user-defined sound cache.
This release includes more than 100 improvements over the one. It also includes CSL 1.6, the latest users guide, 10+ new commands and much more. http://www.nocturnal-central.com/catapult.php