Visual SEO Studio : an SEO audit tool by Federico Sasso which uses a very similar user interface to the one used in Microsoft’s Visual Studio. Comes with a Web Crawler (no limits on the number of crawled URLS) and other interesting features. Good tool if you cannot afford Screaming Frog.
Compatible with Windows 7 and Windows 8. There’s no OS X version yet so I have to use this tool through Parallels Desktop. You can download the latest free Beta here.