One of the huge difference between Dynamics CRM 2011 and 2013 is navigation. Page and menu navigation has changed drastically in Dynamics CRM 2013. In CRM 2011 navigation is done thru left navigation and ribbon menu, however in CRM 2013 it is very user friendly, no left navigation and no ribbon menu, all you have to do just click on any drop down on left top side to go to corresponding page.
Main Modules Navigation: when you click on Microsoft Dynamics CRM drop down, it displays different main module tiles like Sales, Service, Marketing, Settings and Help. Shown in the below screenshot.
Individual Module Navigation: when you click on “Sales” drop down from the main modules navigation, it displays different sales functions available under Sales module. If number of menu items are exceeding in the width of the window, you need to click arrow on the right side to see remaining menu items, once you click on right side arrow, if number of menu items exceeding in the window, you will see arrow on left side too. Scroll Left and Right side arrows to see all menu items under Sales module. Shown in the below screenshots:
Recently Viewed Navigation: when you click on “Accounts” drop down next to “Sales”, It displays the recently viewed Accounts. Shown in the below screenshot.
You can also click on “Accounts” drop down under “Sales” module to check recently viewed records, shown in the below screenshot.
Microsoft Dynamics CRM Blog 
My “Recently Viewed” seems to be working only on Opportunities, Quotes and Orders, but not on Accounts, Contacts, and Leads. We launched Dynamics 2013 on June 2. It is this way for half of the office , not all users. I am using IE browser…thoughts?