Administration menu

Shifts the site output down by approximately 20 pixels from the top of the viewport. If disabled, absolute- or fixed-positioned page elements may be covered by the administration menu.
Displays the administration menu always at the top of the browser viewport (even when scrolling the page).
In some browsers, this setting may result in a malformed page, an invisible cursor, non-selectable elements in forms, or other issues.

Vertical Tabs

Plugins
System tweaks
Moves the tabs on all pages into the administration menu. Only possible for themes using the CSS classes tabs primary and tabs secondary.
Performance