Simple Morse Code application allows you to translate to and from Morse Code, integrates with SMS and Email (send only). The app also plays the text back to you in the pitch / tone you choose - as well as set the speed / Words Per Minute (WPM) comfortable for you (note that older devices cannot play 25 wpm or higher).
The application does not (yet) have a reference or learning section, but one is planned for the next release...