Free iPad app: http://itunes.apple.com/us/app/motion-math-hungry-fish/id483049169?mt=8&uo=4&at=10l6SU
Free iPhone app: http://itunes.apple.com/us/app/motion-math-hungry-fish/id483049169?mt=8&uo=4&at=10l6SU
Free iPad app: http://itunes.apple.com/in/app/tiny-chicken-learns-currency/id511250020?mt=8&uo=4&at=10l6SU
Free iPad app: https://itunes.apple.com/us/app/number-rack-by-math-learning/id496057949?mt=8&uo=4&at=10l6SU
Free iPhone app: https://itunes.apple.com/us/app/number-rack-by-math-learning/id496057949?mt=8&uo=4&at=10l6SU
Google Chrome app: https://chrome.google.com/webstore/detail/number-rack-by-the-math-l/pdblapgbfbphhldogcijidlkbcgokfkc
Website: http://www.mathlearningcenter.org/web-apps/number-rack/
Website: http://illuminations.nctm.org/ActivityDetail.aspx?ID=207
Free iPad app: https://itunes.apple.com/us/app/deep-sea-duel/id547246887?mt=8&uo=4&at=10l6SU
Free iPhone app: https://itunes.apple.com/us/app/deep-sea-duel/id547246887?mt=8&uo=4&at=10l6SU
Free Android Phone app: https://play.google.com/store/apps/details?id=air.AndroidPublish