Chrome certainly lacks an inbuilt session manager like Firefox. Session Manager for Chrome is the perfect way to manage and organize your sessions. The extension saves your session exactly as it was left and you could restore your session at any point of time.
To save a session, you need to tap on the extension icon and click on save. You could name your session and your session would be saved. You could save multiple sessions and choose to open any session with just a click. The next time you fire up Chrome, you could choose to restore any of your sessions and the browser would return to its creation state.
You could even group pages and create sessions for specific times. Unfortunately, the extension has difficulties restoring browser windows. It perfectly restores the state of your tabs, but restoring windows seems to be a problem for the extension. It even fails to remember the history of your saved tabs.