Hi mom77,
Not to be biased, but I am an independent game developer and created a piano sight reading tool for iPad called PIANO SIGHT READING HD. While it may be a little advanced for very new beginners, it really is a neat tool for practicing to read both treble and bass clef and in different key signatures. There is also a built-in piano that projects the note you touch on the musical scale (this is good for beginners for sure).
The best part is, we recently made this free in the iTunes store, so it is a 100% zero obligation download!

Here is the link:
http://itunes.apple.com/us/app/piano-sight-reading-hd/id510269437?mt=8We are also promoting another game for iPad or iPhone called WORD GRIND. It is a spelling game that hopefully appeals to a wide age range (my 6-year old niece enjoys playing it, as does my 60-year old father). It is also free:
http://itunes.apple.com/us/app/word-grind/id528896221?mt=8Thanks for your time, and if you have any feedback on either of these games, I would certainly welcome it!
-James P.
wordgrind@yahoo.com