This app is almost a mashup of Twitter, Facebook and Yelp. You check in, but it's to talk about specific things that you are doing rather than to make pithy (or inane) remarks. The check-in page allows you to say that you are currently reading a book, watching a movie, thinking about a topic, or 6 other options. You can email GetGlue to add other options- and there is my main disappointment; most of the time, what I'm doing is not listed as an option.
Still, there are fun things about this app, and lots of potential. You can see how many others are doing the same thing you are, and others can comment on your posts, allowing you to meet people with similar interests. You can rate books, movies, wines and other things and read reviews on those items.
This app is probably great for people who like Twitter but aren't so good at coming up with things to talk about, but it's also a nice way to meet people with similar interests.
I notice that the app appears to emphasize positive over negative- not that that's a bad thing, but definitely noticeable. For example, you may see that an album's page was visited by 6000 people and that 3100 people gave it a thumbs up. You simply have to surmise that the rest didn't like it. This reminds me of the Facebook "Like" button; but while there is no way to "Dislike" on Facebook, there is a "Not for me" option on GetGlue- it's just that the Not For Me's don't appear to be tallied.