Yes, I couldn't find anything better either. I've seen an application note for a speex port from a competing MCU manufacturer, but that's also just for the M4. I can't seem to find any evidence anywhere of someone porting speex to an M0+, but I'm sure someone must have done it. According to a senior engineer with us Freescale have been working on (or at least considering) a speex port for the M0+. Can any Freescale employees here confirm or deny this?