Alexa is a unique website that reads and analyse other sites when being searched, showing total visitors, demographics, search keywords, backlinks and many more. There are so many other sites that shows web analysis like alexa, examples are cutestat, similarweb, hypestat and iwebchk.
I think to design a site like alexa or any other web statistic site you will need some great wordpress theme for good design and making of the website like hypestat. I have wondered how alexa even generate those analysis information like backilinks, keyword e.t.c .
I think it can be done with the help of some wordpress plugins. If you have any thought on this, feel free to email me beacause i need a site like alexa