Xicheng Dong Published Applications :

Great way to "see" how math works! --by Greg Garner
Awesomely Effective!!! An absolutely amazing and brilliant way to visually demonstrate basic math principles! Thank you! -- by iPad Dad3...
Great way to "see" how math works! --by Greg Garner
Awesomely Effective!!! An absolutely amazing and brilliant way to visually demonstrate basic math principles! Thank you! -- by iPad Dad3...