You can download all of McGraw Hill's Everyday Math Games Apps for FREE through Saturday, April 16, 2011. These math apps work on your iPod, iPhone or iPad. (Unfortunately they don't work on mine since I don't own an iPod, iPhone or iPad *sniff*).
When you click through the link above, you can then click on "View More By This Developer" and it'll launch the iTunes App Store where you can find the other free apps to download. Just double check that the price says "FREE" before you download anything.