I have seen a request for software to check pitch. I have found Anvil Studio (
http://www.anvilstudio.com/). The initial program is free, but there are extra tools you can buy for it. One of the tools is called Music Drills, within that tool is a voice training tool. Whether this works or not I have no idea, I haven't spent the 20 bucks on it.
Supposidly you sing the note into the microphone and it judges if you are singing too flat or too sharp or perfect. I have been tempted alot to try it and think I might one day soon just to find out.