http://suzywells.wordpress.com this is a blog put together by an Elementary teacher. She has found it useful for her and hopes that others will find it useful as well. I found this useful for middle and high school as well. She has lots of great resources listed on the blog.
http://www.arcademicskillbuilders.com has several games for grades k-6 to reinforce academic skills.
http://ipadapps4school.com/2013/03/19/grammar-wonderland-a-fun-grammar-game-for-your-students-ipads/ Looks like a fun app to assist in learning nouns, pronouns, and verbs! Warning it is not free.
http://pitnerm.blogspot.com is a great resource for Elementary Teachers.