The Field Trip app has been available for Android for a while now, though it doesn't seem to attract much attention lately. That is not to say the app isn't maintained and updated, in fact Google updated the Field Trip app just a few days earlier. While the Android app remains, it seems Google Glass users also have a Field Trip app available.
Anyway, while most think of Field Trip as being a smartphone app these days, it was originally created with glass in mind. John Hanke, a vice president of product at Google recently spoke about how the mobile (Android) version of the Field Trip app was intended to simply spread the word about the app. After all, Google Glass has a limited user base at the moment.
That should have the Glass Field Trip app fitting in rather nicely. Similar to how Google Now feeds you information, the Field Trip app will do the same. Just in this case that information will be about nearby sights. Unlike Google Now which seems to be beneficial regardless of where you are, Field Trip seems like it would be more beneficial when you are traveling (as opposed to wandering around your home town).
If you have used the Field Trip app on a smartphone you likely have a good understanding of how this all works. And that statement is only more accurate if you also happen to have experience with Google Glass.
Needless to say, given many have yet to see or use Google Glass at this point -- Google has released a video showing how Field Trip works on Glass. And as a spoiler, if you happen to like venturing into new locations and checking things out -- this will likely make you want to buy Glass when it comes available.