Don’t you wish a few of your regular Chrome extensions worked in Incognito Mode? Actually they can! This awesome little option is available in plain sight and I had missed it for so long.
Go to Settings > Extensions. In the list of installed extensions, you can see the Allow in incognito checkbox available below each extension. Enable it for the extensions you want and you are done! 😊
Tried with: Chrome 31.0.1650.63 and Ubuntu 12.04