AllFacebook noticed the removal as well, as they have pointed out a new blog post on the Facebook Developers Blog that explains a bit as to why the directory was ditched.
"Many developers have been confused about what it means to submit to the App Directory and frustrated by the length of time it took to get approved. As we have looked into this issue, we found that the App Directory drove less than 0.5% of all app installs while a significant number of app installs came as a result of Facebook search. Until now, to be visible in search, you had to submit your app to the App Directory.
Today, we are announcing two updates to decouple the search submission from the directory to make it easier for you to get your app into the Facebook search index:
1. We are removing the App Directory (in its current form) since it does not drive a significant amount of traffic to your apps.
2. We are creating a new, simplified way to get your app into the Facebook search index."
In short, this means that for now, the search bar has been given much more prominence in the app discovery process. Sure, sidebar ads will still likely trigger many more app installs, but now, app developers can submit their apps to the Facebook search index without approval, allowing users to get to them faster. Sounds great, right? Well, it would be, if search currently functioned properly.
I know I can't be the only person who types something like "FrontierVille" into the search bar to find a specific Zynga-run fan page, only to be greeted by user-created or even spam apps/fan pages that may have absolutely no relevance to what I'm searching for. If apps no longer have to go through an approval process to be added to search (and everything really is as open as it seems), doesn't this open the door for so much more clutter? Hopefully, this will all just be a temporary solution to some much larger feature being added to the site that will make finding new apps an enjoyable process, rather than a chore.
Did you ever use the App Directory to find new games to play? Would you like to see a one-stop-shop of sorts for applications on Facebook, where you could browse apps by genre, look at screenshots and the like before playing? Sound off in the comments.