When building Office Graph queries pass the name of your app in the ClientType parameter.
Using Delve is a great way of discovering new content. Even though it shows you content you might have not known about, everything you see, you can see because you are allowed to.
Recently, during my Office Graph presentation at the SharePoint Connect Amsterdam, I mentioned a few hidden gems in the Office Graph API. Those capabilities have just been included in the official Graph Query Language documentation on MSDN.
Building solutions with Office Graph
Earlier this week I had the honor of presenting a session about building solutions with Office Graph at the annual SharePoint Connect 2014 Amsterdam.