This application is an upgrade of the original APEX-AT-Work Example application.
It includes lots of new examples, a new layout, new techniques (like screen casts) and an extended documentation.
I myself had a really hard time understanding all these different components, options and functions and their possible integration into APEX.
Of course most examples are not the GOLD medal yet because I'm still studying myself.
But like I said before. APEX needs to increase its graphical standard and with ExtJS there is a great way to achieve this goal.
Hope you will enjoy discovering this application and at the end make APEX even more popular to the world out there.