I don't really care what this is, but I applaud google for sticking with normal names for their applications/products. 'Inbox' is simple and effective, just like their 'Drive', 'News', "Calendar', 'Maps' etc...
Nothing has been a more annoying peeve of mine lately than to see every new app from every new startup in the valley having to come up with some stupid, stupid name for their app; usually missing a letter (Flickr, Tumblr) or appending some sort of -ster or -ly or -li on the end of the name in some vain attempt to be part of the cool crowd.
I'm not the only person to think this it seems:
Silicon Valley's Stupid Name Problem, Visualized