Off Page Optimization Tools:
SEOquake
It is a popular SEO Tool for Firefox, Chrome and Opera browsers. It helps to get information about PageRank, Keyword Density, Google Index, Alexa Rank, highlights no-follow and much more. You need to add the extension in your browser for this.
Seoreviewtools
It features 24 plus online SEO tools to improve your website and your online strategy. Website Authority checker, Keyword suggestion tool & internal link checker.
Website grader
It is a free online tool that grades your site against key metrics like performance, mobile readiness, SEO, and security.