If you control-click or right-click on the icon you'll notice that on old sketch files, not updated to the new 3.1 format, will show "Show Package Contents"

Files in the new format will NOT show "show package contents" in the menu. The fact that they are shown as the file type of "Sketch Drawing (Old)" seems erroneous.

Another one to look into: http://www.adonit.net/jot/touch/

The new Jot Touch has Creative Cloud integration — I guess they're opening this up to third-party hardware devs.

So, technically bootstraps columns are 8.33333333% with a 15px padding on each side. So, the width of the columns are actually 67.5px with 30px gutters.

See my grid settting example: http://cl.ly/VBqO

I remember sitting in front of the commodore with a joystick (maybe a mouse), drawing each pixel. :)

About 1988, designed on a Commodore 64. I think I was in 4th grade. https://www.flickr.com/photos/iansoper/6977923221/

I've used both LayerVault and Pixelapse before. Both have their strengths, but LayerVault is the winner from my perspective.

LayerVault is really ahead of the curve with improvements and is consistently releasing new features, like Delivery (Presentations), PSD LayerComp support, Sketch Support (including previewing artboards and pages), and now the automatic asset creation they released today. It is the more pricey solution, despite that, my vote goes with LayerVault.