I brought this topic up some time ago, but wanted to resurface it. I am using multiple plugins on my site that integrate with the Google PHP API. With the exception of Appointments +, they are all using the beta version of the API, which supports multiple plugins. I would love to take advantage of the Gcal integration in Appointments +, however because the plugin does not use the latest API, it is incompatible with the other plugins. The latest Google PHP API has been in beta for a long time BUT they claim it is stable: "We're comfortable enough with the stability and features of the library that we want you to build real production applications on it." Any chance you will upgrade Appointments + to use this library which supports multiple plugins on a single Wordpress site? Thanks for any feedback!