There exist many iPhone/iPod apps with different sorts of morse applications. The cw training program Ham Morse by AA9PW is outstanding. Cost is only 5 USD. Read more here.
The Morse Code Decoder from HotPaw can decode audio cw. This is good for training and also for decoding high speed cw. To use it you must have an iPhone or an iPod Touch with a mic input. Price for this one is also only 5 USD. Read more here.
A test I did with these two cw apps was to run the Ham Morse on one iPod Touch connected to a loudspeaker and a second iPod Touch connected to a mic and running the Morse Code Decoder. This worked flawless. See this video.
And then today I tested the Morse Code Decoder with an iPod Touch listening, via an external mic, on a Yaesu FT-857D on the 7 MHz band. See this video.
Some days ago I did load the Morse Code Decoder and could not resist that at once to try it. I tuned the 80 m band and some high speed cw stations were easily decoded. Suddenly the word paraset came up on the iPod screen. It was SM6AAL on the the Swedish west coast in QSO with an SP2 station. And SM6AAL was using his 5 W WWII Paraset home-built replica spy station. I had a wire on my balcony and without a tuner and with a very high WSWR, only God knew how high, I called him with my FT-857D/20 W. After several calls he came back with a report and we did complete a QSO. For him down in the noise and by me with my usual S8-9 disturbancies at my QTH here near Stockholm. I got an e-mail from Bertil, SM6AAL with a photo of his spy station. Woow what a station!