Everyone panic! The HBO app is no longer listed in the Google Play Store! Game of Thrones starts in three weeks, how are we going to - wait, what's that? HBO Go is still there? Oh, it's the other HBO app that's gone. The one that doesn't stream episodes and movies. The one that no one uses. Well that's all right, then.
Yes, HBO fans, you can rest easy: nothing is happening to HBO Go, the cable service's streaming app that's free for subscribers. The previous HBO app, which featured a television schedule and various behind-the-scenes goodies, seems to have been un-published. You can still see the app's information over at Appbrain, where the official listing is sporting what look like screenshots from an HTC G1. Downloads have been relatively flat since November of 2012.
The trailer and second-screen features in the original HBO app are pretty much entirely duplicated by HBO Go, and once you've logged in you can stream any currently-playing movie and a huge backlog of original HBO programming. The removal of the basic HBO app means that there's no easily-accessible HBO schedule for mobile devices, but if you're that invested, there are plenty of alternatives (including those that come straight from the cable and satellite providers).
The basic HBO app was downloaded from the Play Store less than a million times. By contrast, HBO Go has somewhere between five million and ten million downloads. I think it's safe to say that no one is weeping over its passing.