Dale Ehrhart has created multiplication and addition Pair Boards for the cool Palm freeware, Dropairs. Dale has created nine Pair Boards for multiplication and nine Pair Boards for addition in both HiRes (like Tungsten E and Zire 72) and LoRes (like Zire 31, Dana, and older handhelds). You can download these boards and many others from the NorthGlide Download Pair Boards page.
I have created my first Pair Board. It's for second graders at my school and is about government. It is very specific to our curriculum, but that's the point. Since you can make your own Pair Boards, you can customize Dropairs for your curriculum and for your students! Feel free to download my 2nd Grade Government Pair Board (HiRes only).
NorthGlide wants you to feel free to make your Pair Boards available to others. You're invited to send your Pair Boards to firstname.lastname@example.org to share with others, just like Dale has.