Websites for Common Core curriculum materials

Our department is starting to plan for our transition to a common core curriculum, so I am keeping my eyes open for materials.  I've found two recently, one is Mastery Connect (www.masteryconnect.com).  This site creates a common place for people to upload assessments that are categorized by common core standards.  They also provide a gradebook for keeping track of student's mastery of the standards.  The service is free, but there is a charge for some of the more advanced features.  The other site I have found is LearnZillion (www.learnzillion.com).  The site has lesson plans listed by common core standards.  The lesson plans are typically videos and power points.