Listed below are links to online math games.
http://www.xpmath.com/ - login to submit scores
http://www.sheppardsoftware.com/math.htm
http://www.kidsmathgamesonline.com/
http://www.mathblaster.com/ - requires parent approval
Adding/Subtracting Integers:
http://www.aaastudy.com/add65_x2.htm
http://www.321know.com/subint1.htm
http://www.math-play.com/integers-game.html
http://www.funbrain.com/cgi-bin/nl.cgi?A1=s&A2=4
http://amby.com/educate/math/integ_x1.html
http://www.mathgoodies.com/games/integer_game/football.html
http://pbskids.org/cyberchase/math-games/space-coupe-rescue/
http://www.arcademicskillbuilders.com/games/spider-match/spider-match.html
http://www.berghuis.co.nz/abiator/maths/sa/saintegeradd2.html
http://www.arcademicskillbuilders.com/games/orbit-integers/orbit-integers.html
Multiplying/Dividing Integers:
http://www.aaastudy.com/mul65_x2.htm
http://www.aaastudy.com/div65_x2.htm
http://www.math-play.com/multiplying-and-dividing-integers-game.html
http://www.berghuis.co.nz/abiator/maths/sa/saintegerdivision.html
http://www.berghuis.co.nz/abiator/maths/sa/saintegermultiply.html
http://www.arcademicskillbuilders.com/games/integer-warp/integer-warp.html
http://www.xpmath.com/forums/arcade.php?do=play&gameid=58
http://www.xpmath.com/forums/arcade.php?do=play&gameid=17
http://www.xpmath.com/forums/arcade.php?do=play&gameid=16
http://connectedmath.msu.edu/CD/Grade7/IntProdGame/IntProdGame.html
All Operations:
http://www.quia.com/cb/64603.html
http://www.math-play.com/Integers-Jeopardy/Integers-Jeopardy.html
http://studymaths.co.uk/games/nastynegatives.html
http://www.homeschoolmath.net/choose-op/choose-operation-game.php?mi=-10&ma=100
Various Games
http://catchupmath.com/math-games/
http://jmathpage.com/middleschoolmath/middleschoolmath.html
http://jmathpage.com/middleschoolmath/jmsmlogicproblemsolving.html
The following hyperlink is a list for over 20 math apps for the iPad.