Integrated Gmail is a Firefox extension for the lovers of simplicity, there are many more options than you think of using Gmail in a minimalist way.
Just install this addon and your Gmail is reduced to an abstract, in fact a link, with total unread messages. Then we can add other things under it like Google Apps, Google Maps or Google Reader.
Whenever, you want to see through your emails just click and as we see in the picture, it all comes down to a simple interface and fill our screen. Something that contributes to the fact that links us to use Google services which will be expanded or collapsed accordingly, so that when not in use are minimized.
Allows you to make the Inbox Collapsible and loads your choice of Google Calendar, Reader, Notebook, Groups, Maps, Picasa, Sites, News and Portfolio plus Custom URLs (w/navigation buttons innframe) and Google Gadgets seamlessly into the Gmail interface below the inbox (rather than the sidebar) using a collapsible box. If your are inbox minimalist, enable minimalist mode to clean up the inbox even more.
Integrated Gmail Addon
Related: Trick to show emails from another account in Multiple Inboxes
Download Integrated Gmail Addon
Learn about their population. ,