Mastery Connect is a network where teachers can share formative assessments that are tied to common core standards. You get all that for free. The premium version is definitely intriguing, because it allows you to track student mastery of standards in a very easy way. Oh and their common core app is pretty sweet, too.
All too often, we forget about the concerns of urban students. This post is well written and thought provoking, and its assertion that standardized tests can have value may challenge your current thinking.