Now, there is a new free tool which can use to find backlinks. You just type in your competitor's domain name in the blank space and then click on Explore.
It will show you the Domain Rank, Linking Domain, Total Back Links, Top Pages on that domain, and even whether they are do-follow or no-follow. It also tells you precisely what they link to, the number of Outbound Links on that page, and other info.
The tool is called Sheer Explorer. You can check it out at: http://www.SheerExplorer.com