Here's a list of keyboard shortcuts for the Windows or Web app:
Dashboard: ⌥ + A \ Alt + A
Styleguide: ⌥ + S \ Alt + S
Jump to Next Screen: →
Jump to Previous Screen: ←
Jump to Screen: ⌥ + J \ Alt + J
Zoom In: ⌥ + + \ Alt + +
Zoom Out: ⌥ + - \ Alt + -
Actual Size: ⌥ + 0 \ Alt + 0
Pan screen: Space
Manage tags: ⌥ + T \ Alt + T
Search screen: ⌘ + F \ Ctrl + F
Clip screen thumbnails: ⌃ + ⌥ + T \ Ctrl + Alt + T
Show/hide screen grid: ⌥ + G \ Alt + G
Navigate between list items (e.g. versions of a screens): ↑ and ↓
Expand sections: Ctrl + Alt + ↓
Collapse sections: Ctrl + Alt + ↑