I am using iThemes Builder Child Foundation Blank latest version on WordPress 3.6.1. I just donated and wanted to thank you for the years of work you've put in on this and the outstanding results. This plug-in is intuitive, flexible, and plays perfectly well with other plug-ins I use, including those found in the iThemes Web Developer's Toolkit. It frees me up to focus on content and design rather than worrying about use case UI considerations for every type of post navigation requirement. Work like this is what makes WordPress valuable. My thanks.