Cleaned-Up Links in Sidebar

It feels good to clean older references from the sidebar and, more importantly, to highlight the newer demo and docs that went live last year. I really need to work on revamping the whole site as planned for this year, but for now, these minor tweaks should do.

Please visit the slightly modified mobile UI demo — the touchscreen swipe simulation gets easy fast even using a touch pad. And do read up on the help pages and IPP documentation.