I'm trying to find some good math animations, tutoring programs, activities, etc. So far the Droid Market is leaving much to be desired. I found:
A grapher that is less sophisticated than the graphing calculators the students already have
A statistics quick reference that is just pages from a textbook
An app that is nothing but a formula quick reference sheet
A math "game": if you get a bunch of math problems right, you unlock a game that has nothing to do with math
A series of tutoring lessons that are all audio, no visual at all
A tutoring app that will walk you through solutions steps but has no real explanation of those steps
Among the crap, I did find one promising app for statistics: DroidSurvey is designed to do market research. It allows you to set up a survey, and then walk around with your tablet and have people answer the survey right there on the tablet. Unfortunately, it doesn't calculate any statistics--you have to download the data to your computer and use a statistics program to do that.
So, disappointed with the available apps. As much as I hate Apple, I'm wondering if I should have gone with the iPad.