Check out the menu on this site: http://piwik.org/.
Click the Learn More button.
See how it pans to the side and the small arrow appears, anybody know how to achieve this effect?
Most templates based on bootstrap share this effect and others similar to this (they use JQuery and integrate it into the boostrap template). You may want to do a Google search and see what you find.
I had a link to a page that I really love (can’t remember the URL because it is in my fav list in my pc at home and I don’t pay attention to the address bar anymore 
) where you could see effects like this and the code for them.
Found it!
This menu is somehow similar to what you want
I’m not sure which terms I should use to get that exact effect (they have so many cool effects that you may want to use some other effect instead)
This other may be helpful too