So, how did they pull it off? By reusing a lot of assets and focusing in tightly on what they needed to create. Many of the art assets came directly from Nightclub City. InCrowd's basic idea is that it's a virtual space check-in game, so there's a persistent avatar that visits virtual backgrounds, and most of the basic avatar art and style all came from Nightclub City. Outside of the art design, Booyah stuck to a laser focus on gameplay. Players can check-in to earn currency, then they can interact with their friends' avatars in very simple ways. Anything more complicated and Booyah might not have finished the game in time for Facebook Places' launch.
The game's team consisted of 12 people in various positions, but they were all busy on other work as well during development. Parise said the team tried to meet as little as possible. All meetings were held only by demand; they started out small and only brought more team members in when needed. Rather than going for a "hackathon" or a four-week long crunch, Booyah instead planned as tightly as they could and stuck to the schedule. A fully-distributed build of the app was done by 7:09pm on the very first day of the project, and Booyah's already-existing server platform and software was all used where it could be.
Much of the finished app is actually WebViews, special iPhone app pages that simply pull in browser views of Booyah-created Web pages. This was doable because the app tied directly into Facebook (which means you need to be online to use it), and it allowed Booyah to quickly and easily edit app content, mostly outside of Apple's approval process. It allowed them to keep things simple (rather than building a full iOS UI, they only had to develop a Web page), and it let them use widgets and Facebook code where they could, rather than dealing with an API and iOS code all the time.
Did it work? Parise couldn't go into detail on how popular InCrowd actually is, and he says that the recent Facebook outages haven't helped the app's reception, even though most of those problems are beyond Booyah's control. But he said that players enjoyed the check-in process as a game, and when they were in an area with a lot of Facebook Places to check-in to, they enjoyed the location and friend discovery that the app offered. Parise also said that, as a developer, the quick process actually created some nice "accidental features." He learned to use a loading screen to offer up more customized information than Booyah originally planned to do, and the "Limbo" that players started in during development (before they actually checked-in to wherever they happened to be) organically grew into a "Home Base" idea that really resonated with players.
In the end, though, Parise says that while creating the game "was a great experience," he couldn't recommend the process to other developers. Certainly there are always time restraints on development, and all developers need to make what they can in the time they have before release, short as that may sometimes be. But from what Parise said, even with the very focused development style that Booyah used to make InCrowd, creating such a simple app so quickly definitely isn't the ideal way to develop App Store software.