Mac OS Developer Tools
KFCaffCon OSX - small powerful sound converter for iOS Developer
KFCaffCon OSX is an interface for afconvert - done right. Small but yet powerful, it lets you convert a single file or batch convert a bunch of files by just dropping them onto KFCaffCon.
Choose a bitrate for getting the best sound quality with minimal file size. Depending on your workflow, you could choose a destination folder or just have your converted files sit next to the original ones.
You haven't heard the best part yet: transmit the result to KFCaffCon for iOS for pre-listening the sound on your iOS device.