New apps are coming out all of the time. Here is a recommended list created in May 2013. This list includes math apps used in the classroom as well as apps that may be used at home. Some apps may require an account. Please feel free to leave comments about your experiences with these apps.
Free iPad app: https://itunes.apple.com/us/app/todo-math-kindergarten-to/id666465255?mt=8&uo=6&at=10l6SU
Free iPhone app: https://itunes.apple.com/us/app/todo-math-kindergarten-to/id666465255?mt=8&uo=6&at=10l6SU
Free Android Phone app: https://play.google.com/store/apps/details?id=com.enuma.todomath
Free Android Tablet app: https://play.google.com/store/apps/details?id=com.enuma.todomath
Paid iPad app: https://itunes.apple.com/us/app/math-doodles/id526959716?mt=8&uo=4&at=10l6SU
Paid iPhone app: https://itunes.apple.com/us/app/sums-stacker/id343251346?mt=8&uo=4&at=10l6SU
Paid iPhone app: https://itunes.apple.com/us/app/connect-sums-math-doodles/id555216734?mt=8&uo=4&at=10l6SU
Free iPad app: http://itunes.apple.com/us/app/motion-math-zoom/id451793073?mt=8&uo=4&at=10l6SU
Free iPhone app: http://itunes.apple.com/us/app/motion-math-zoom/id451793073?mt=8&uo=4&at=10l6SU
Website: http://www.khanacademy.org/
Free iPad app: https://itunes.apple.com/us/app/id469863705?mt=8&at=10l6SU
Free iPhone app: https://itunes.apple.com/us/app/id469863705?mt=8&at=10l6SU
Free Android Phone app: https://play.google.com/store/apps/details?id=org.khanacademy.android
Free Android Tablet app: https://play.google.com/store/apps/details?id=org.khanacademy.android
Edmodo app: https://spotlight.edmodo.com/product/khan-academy,324527/
Free Android Phone app: https://play.google.com/store/apps/details?id=com.brainpop.brainpopfeaturedmovieandroid
Google Apps for Education app: https://www.google.com/enterprise/marketplace/viewListing?productListingId=8006+9291735389906767602
Free iPad app: http://itunes.apple.com/us/app/brainpop-featured-movie/id364894352?mt=8&uo=4&at=10l6SU
Free iPhone app: http://itunes.apple.com/us/app/brainpop-featured-movie/id364894352?mt=8&uo=4&at=10l6SU
Website: http://www.brainpop.com/
Google Chrome app: https://chrome.google.com/webstore/detail/brainpop-featured-movie/cdikkckjinnmjpgkjjpnfmmbcpbhmklf
Website: http://www.ixl.com/
Paid iPad app: https://itunes.apple.com/us/app/motion-math-hd/id410521340?mt=8&uo=4&at=10l6SU
Paid iPhone app: http://itunes.apple.com/us/app/motion-math/id392489333?mt=8&uo=4&at=10l6SU
Edmodo app: http://www.edmodo.com/publisher/motionmath
Paid iPad app: http://itunes.apple.com/us/app/fractions-app/id387434956?mt=8&uo=4&at=10l6SU
Paid iPhone app: http://itunes.apple.com/us/app/fractions-app/id387434956?mt=8&uo=4&at=10l6SU
Paid iPad app: http://itunes.apple.com/us/app/factor-samurai/id441919897?mt=8&uo=4&at=10l6SU
Paid iPhone app: http://itunes.apple.com/us/app/factor-samurai/id441919897?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
Paid iPad app: https://itunes.apple.com/app/wolframalpha/id334989259?mt=8&uo=4&at=10l6SU
Paid iPhone app: https://itunes.apple.com/app/wolframalpha/id334989259?mt=8&uo=4&at=10l6SU
Paid Android Phone app: https://play.google.com/store/apps/details?id=com.wolfram.android.alpha
Paid Android Tablet app: https://play.google.com/store/apps/details?id=com.wolfram.android.alpha
Paid iPad app: https://itunes.apple.com/us/app/math-bingo/id371338715?mt=8&uo=4&at=10l6SU
Paid iPhone app: https://itunes.apple.com/us/app/math-bingo/id371338715?mt=8&uo=4&at=10l6SU
Paid iPad app: https://itunes.apple.com/us/app/montessori-numbers-for-kids/id547209737?ls=1&mt=8&uo=4&at=10l6SU
Paid iPhone app: https://itunes.apple.com/us/app/montessori-numbers-for-kids/id547209737?ls=1&mt=8&uo=4&at=10l6SU
Free iPad app: https://itunes.apple.com/us/app/playful-minds-math-5-8-years/id449569846?mt=8&uo=4&at=10l6SU
Free iPhone app: https://itunes.apple.com/us/app/playful-minds-math-5-8-years/id449569846?mt=8&uo=4&at=10l6SU
Website: http://www.mathplayground.com/
Free iPad app: https://itunes.apple.com/us/app/mathletics-student/id560955922?mt=8&uo=4&at=10l6SU
Free iPhone app: https://itunes.apple.com/us/app/geoboard-by-math-learning/id519896952?mt=8&uo=4&at=10l6SU
Free iPad app: https://itunes.apple.com/us/app/geoboard-by-math-learning/id519896952?mt=8&uo=4&at=10l6SU
Website: http://www.mathlearningcenter.org/web-apps/geoboard/
Google Chrome app: https://chrome.google.com/webstore/detail/geoboard-by-the-math-lear/gaakmmdiopnmcenkojohldanladpajak
Paid iPad app: https://itunes.apple.com/us/app/slice-fractions/id794730213?mt=8&uo=4&at=10l6SU
Paid iPhone app: https://itunes.apple.com/us/app/slice-fractions/id794730213?mt=8&uo=4&at=10l6SU
Paid Android Phone app: https://play.google.com/store/apps/details?id=air.com.ululab.SliceFractions
Free iPad app: https://itunes.apple.com/us/app/questimate!/id610665063?mt=8&uo=4&at=10l6SU
Paid iPad app: https://itunes.apple.com/us/app/lattice-multiplication/id351024204?mt=8&uo=4&at=10l6SU
Paid iPhone app: https://itunes.apple.com/us/app/lattice-multiplication/id351024204?mt=8&uo=4&at=10l6SU
Paid Windows program: https://www.microsoft.com/en-us/store/p/lattice-multiplication/9njmfskk8v9h
Paid iPad app: https://itunes.apple.com/us/app/visual-fractions-decimals/id696974837?mt=8&uo=4&at=10l6SU