I’m not aware of any apps in the iTunes App Store that will record audio and allow it to be saved as an .mp3 file, which is probably the most widely accessible audio file format. However, I heard about the Hokusai app from Joe Dale on Twitter earlier this year. Joe works in Modern Foreign Languages and writes on his own Blog. The Hokusai app, available for iPhone and iPad in the iTunes Store, is a neat little app. It is very easy to record audio using this app. It saves it as a .wav file (uncompressed) or a MPEG-4 file (compressed) but not .mp3. However there is a way around this.
Record some audio using the Hokusai app. Within the app, you then have the option to export the recording to your Dropbox account as a Wave file. Then open the Audacity free audio recording/editing software on your PC or Laptop. Import the Wave file that you recorded from your Dropbox acccount (you may have to copy the file onto your PC/Laptop first) into Audacity and then choose to export the Audacity file as an .mp3. This podcast can then be embedded into a website or blog for people to listen to.
This is a roundabout way of creating MP3 sound files, but it is handy to be able to record audio while on the go and then to be able to convert them into .mp3 files to share with others.