OK this is an update as of 15th Nov 2014.
Big changes in the theme this week:
1. New Layout System
2. Breakpoints is now a dependancy
3. Updated Responsive Menus
The biggest change in the last few weeks is the layout system. After much thought I came to the conclusion that I should go back to my original idea and build layout per region, rather than switching whole-page-layouts you now set the layout by breakpoint and row. This is an extremely flexible and powerful system what allows you to select any breakpoint group, generate template suggestions and set the layout for each breakpoint and each "row" within the page. I will make a video very shortly to demonstrate how this works and how to use it.
Breakpoints Module is now a dependancy
Breakpoint is a Drupal core module and is enabled by default on a standard install since Toolbar uses it. The theme now relies on Breakpoint to provide its media query breakpoints which are stored in yml files inside AT Core.
AT Core ships with two Breakpoint groups - AT Core Simple and AT Core Advanced. The simple group has just three pretty basic media queries but the advanced has 6 media queries that interact in a pretty complex way, they can be used together, for example using the Advanced group for Layout and the Simple for Responsvie menus, in fact you can combine any group (for example from another theme or module such as Toolbar).
Breakpoint module allows you to add your own breakpoints to your theme or module and use them anywhere, for example you can use the same breakpoint in Responsive Images module in Drupal core.
Responsive menus extension has been revamped, you can now set the breakpoint group. You can set a default menu style and one breakpoint for the responsive style. It can support a mobile first or desktop first approach. Options include Slidedown (standard hamburger menu), off canvas (left and right options), drop menu, standard horizontal menu (no drop downs), tiles and standard vertical menu. Tiles allow you set the number of tiles.
The responsive menus system is quite new and certainly requires more testing before release, especially on touch devices. We are running a double-tap script that can detect the first tap and open a sub-menu (for example with drop menus on touch screens).
There are a huge amount of other updates, far to many to detail here, instead I will be making a series of videos on the various extensions and features in the theme, and much help to get started using it.