Chrome: The person who invented browser tabs was obviously a genius, but it left us with the problem of managing multiple open tabs. Spaces makes it easier by allowing you to save and jump between open windows of various tabs.
The extension will show you a list of all the open Chrome windows you have at a time, show you which tabs you have open in each one, and quickly jump between them. Handily, you can open a few tabs in a window, give the space a name, and then you can quickly open them later. This is particularly handy when you have a few tabs you need for a given task, but don't want to keep them open all the time.