SpellingCity is a wonderful site for teachers to help students strengthen their spelling and vocabulary skills. This is done by searching through or creating your own word lists that can then be imported into interactive learning games. Also, there is excellent free iOS app that interacts w/ users of the SC site.
Showbie is a wonderful site/iPad app that I found out about from Edshelf. This is an app that interacts w/ the Showbie site where teachers create classes and assignments. Once this is done students can then use the iPad app to share files and turn in assignments. Teachers can then evaluate student work using their Showbie iPad app as well.
FluencyFinder is a wonderful iOS app for assessing student reading levels. This is done through a very easy to user interface where teachers print out Reading passages Grades 1 - 8 and then have students read along while marking their mistakes on their mobile device. Best of all students are created on their mobile device and all student and data tracking is done automatically which then generates reports.
The Answer Pad is a great free iPad solution for assessing student data. This is done by registering and interacting w/ a free iPad app that allows teachers to create student accounts and answer sheets, and then assess student data.
Boom Writer is one of my favorite Web 2.0 site and is a very innovative way to integrate technology into a curriculum. This is done by having a class grades 3-8 create a digital story through an online competition in a safe environment. Students create chapters and then vote on which chapters should be included in the finished product. Once a book is completed it can then be published and a copy can be ordered. Right now BW offers a free class copy for new teachers that sign up. 
Online Audio Cutter is a handy little site I found out about from Free Technology 4 Teachers. This site site allows users to edit/cut audio from YouTube and Sound Cloud clips by pasting in a URL.
