All your favourite apps and tools, integrated with Ghost. This integration system brings super power in ghost. You want to add Google Analytics to your site? Just get your tracking code and add that to your site using Ghost's code injection option. Or if you want to use other analytics tool, there are 9 analytics tool which can be integrated with ghost.
If you are missing any apps which you like to use with your Ghost site then you can try Custom integration. Most likely there is a way to use your app with ghost via custom integration. You can always head over to Ghost community forum and search for possible solution.