Here’s an excellent free app to let you hear Morse Code, preferably through your earphones so your neighbors don’t look at you and roll their eyes, called CW Morse Trainer. You can set your speed as well as waveform, qsb, spacing and dot-dash ratio but I only mess with speed. You can listen to a QSO, hear a series of more-or-less random English words, your own text mode, ebook mode, groups of five scrambled characters (i.e., not words from a real language), and callsigns. I have improved a lot by using the Callsign mode because you have to keep your head ready for letters and numbers, plus an occasional “slash.” I like it.
Get it from your Android Market and check them out at http://www.wolphi.com. They have a few other amateur radio apps that may interest you.