This app is not cross-platform yet. On my Macintosh the following message emits after recording and then pressing the Play button:
Elapsed time is 2.332205 seconds.
Error using wavplay (line 37)
WAVPLAY is only for use with Windows machines.
Error in AutoTuneToy>play_button_Callback (line 672)
Error in gui_mainfcn (line 96)
Error in AutoTuneToy (line 42)
Error while evaluating uicontrol Callback
According to the documentation
Note: wavplay will be removed in a future release. Use audioplayer instead.
11 Dec 2012
Allows you to record and graphically manipulate and pitch correct your voice.