Best online German dictionary
http://dict.leo.org/ende/index_de.html
Quizlet
Level One: http://quizlet.com/join/UjcZm9gPc
Exploratory: http://quizlet.com/join/VzUbXGCtZ
Exploratory: http://quizlet.com/join/VzUbXGCtZ
Duolingo
https://www.duolingo.com/course/de/en/Learn-German-Online
Play FreeRice in German
http://freerice.com/#/german/14636
Memrise
http://www.memrise.com/home/
Gaggle
https://www.gaggle.net