The Wayback Machine - https://web.archive.org/web/20130216041554/http://design.ubuntu.com:80/apps/get-started/ui-model

UI model

We want people to be able to quickly access their content and move between their apps. That’s why we use natural swiping gestures from the edges of the screen.

UI_model

Definitions

Settings and system services

Time and date, volume, network, messaging and battery; these settings and services can be accessed directly from the top edge.

Return to previous app

A swipe from the right edge takes you back to the last app you were using. Another swipe takes you back to the application you used before that.

Controls

Swiping up from the bottom edge of the phone reveals app controls. You can hide or reveal them instantly, which means they don’t take up room on the screen.

Launcher and Dash app lens

A short swipe from the left edge of the screen reveals your favourite apps. A full left-to-right swipe reveals a screen showing all your running apps.