iPad Games

http://www.scaleblitzer.com/
ScaleBlitzer is an iPhone and iPod app for blitzing your scales! Also works on iPad.

https://itunes.apple.com/us/app/piano-maestro-by-joytunes/id604699751?mt=8
Fun & interactive iPad app for sight-reading and learning new music.

THEORY Games and DRILLS

http://www.musictechteacher.com/music_quizzes/music_quizzes.htm
Levels: beginner through late intermediate
Topics: instruments, composers, musical terms, note identification, and rhythm
Format: interactive games and quizzes

http://www.emusictheory.com/practice.html
Levels: beginner through intermediate
Topics: note and key recognition drills
Faves: Note Names, Paced Note Names, Piano Keys, Rhythm Dictation

http://makingmusicfun.net/htm/printit_notename.htm
Levels: beginners
Topics: note reading, intervals, rhythms
Format: printable worksheets

Theory Tutorials

http://www.teoria.com/
Best for TUTORIALS (not so much for games). Intermediate/advanced.

http://www.good-ear.com/
Useful for advanced students with previous experience wanting to practice interval, chord, and cadence identification on their own.

http://www.musictheory.net/exercises
No-frills drills in note recognition. Good for adults - beginners through late intermediate levels.

http://www.nfmc-music.org/index.php?src=gendocs&ref=Festivals
National Federation of Music Clubs Theory Tests/Answers

Music Notation Software

http://musescore.org/
http://www.noteflight.com/login
http://www.finalemusic.com/products/finale-notepad/
http://iwritemusicapp.com/