I'm not on the community development team, so I don't know if anything like this is planned or already in the works.
However, based on the current iPhone version of the app, it seems simple (to me) or add an
Escrituras link right below the
Scriptures link within the app that then links to the appropriate Spanish MP3s. But what seems simple to me likely requires lots of coding and testing to pull off.
Until Spanish gets added to the app(s), MP3s of the LDS edition
old and
new testaments are available. MP3s of the Spanish versions of the Book of Mormon, Doctrine and Covenants, and Pearl of Great Price are also available for download at this link:
http://lds.org/mp3/newarchive/0,18615,5249-1,00.html
General Conference in Spanish is available for download at this link:
http://lds.org/general-conference/sessions?lang=spa