In 2011, Josh Miller left Princeton during his senior year to co-found a group blogging startup, Branch.

Branch went on to raised $2 million from a bunch of notable investors and was advised by Twitter co-founders Evan Williams and Biz Stone. In January, it was acquired by Facebook for an estimated $15 million.

Since then, Miller and his Branch team have been working on a stealth new app for Facebook's Creative Labs group. As part of that, he gets to have frequent meetings with Mark Zuckerberg to discuss the app's direction.

Today, Facebook is announcing what Miller is working on. The app is called Rooms, and it hopes to revive the old yet popular idea of Internet forums on mobile devices. It lets users create forums for content they're interested in. Then the administrator can invite other like-minded people to contribute to the feed with a unique QR code.

Early reports suggested Miller's stealth project was a clone of popular anonymous apps Secret and Whisper. For Miller, it's strange to have preconceived notions about what he's building just because he's part of Facebook. Facebook has been accused of cloning other popular apps such as Snapchat and TapTalk recently.

While the app has some anonymous components, Miller's app Rooms is more like WordPress or Tumblr than a gossip-swapping site.

"The reason people got excited about the Internet was because they realized, 'Wow, I can find other common people to me,'" Miller said of the inspiration for Rooms.

For example, if you're interested in the Syracuse Orange, you can create a "SU Basketball" room, write a quick description, tweak the appearance of the feed, and get a discussion going.

Here's what a room on "beekeeping" might look like.

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Rooms look a lot like the layout of popular app Secret, where a large photo from a camera roll can be overlayed with text or icons. Links and videos can also be added to feeds.

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Rooms are easily customizable in terms of privacy settings, color backgrounds, and even like buttons. For example, if you would rather have forum contributors express appreciation with a beer mug emoji and the word "Cheers!" than a thumbs up and "Like," you can set that up.

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Each room has a unique QR code that can be screenshotted by an invitee. When that invitee opens Rooms, the app automatically recognizes the QR code in the user's camera roll and lets them into the forum.

Rooms isn't tied to Facebook or mobile contact lists at all. Signing up for a room requires you to create a user name of your choice, but you can have multiple user names on the app. No identifying information is collected, which is very unlike Facebook. So, much like comments sections on websites or traditional forums, fake names can be used rather than true identities.

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Facebook is striving to remove all branding from the experience, the way WordPress lets blogs like TechCrunch use it without flashing its logo everywhere.

Miller's team has been working on Rooms for the last six months, most recently in London where they're spending a year collecting tech talent and collaborating with iOS guru, Alan Cannistraro. Cannistraro created some of of Apple's classic apps, such as iBooks.

Rooms, Miller says, wasn't a shower idea and there was no "aha!" moment for it. It didn't stem from a Facebook hackathon, like Slingshot did, either. 

"When we joined Facebook, we were considering a few other companies," Miller says of the acquisition. "Facebook was really stoked about having us work on the same problems here. What we realized at Facebook is, if you add up all the forums and message boards across the Internet, it's huge. But there are no forum apps in the top 100 mobile apps."

The product is almost too simple. There isn't a search functionality for people who are interested in participating in like-minded rooms, for example. Miller says there are a bunch of features Rooms is leaving out of launch on purpose. 

"We thought, 'Before we make this more complicated, let's see what people think," Miller says. Rooms will observe how people use the product and build out features accordingly.

Miller says Mark Zuckerberg has been excited about Rooms and his team has had monthly meetings with the Facebook CEO to discuss the app's progress.

When asked if he ever thinks about the fact that he was a college student three years ago, and he's now having monthly meetings with the head of Facebook, Miller laughed and said his close friends keep him grounded.

--This story first appeared on Business Insider.