Last year, there were plenty of rumors that Facebook was working on building a phone of its own. Ultimately, a pair of humdrum devices with a simple “Facebook button” ended up hitting the market, and the rumors stopped… until now. On Monday, AllThingsD said it has learned that Facebook is working closely with HTC on a new phone currently codenamed “Buffy.” The device will supposedly run a modified version of Android that, obviously, will put Facebook’s services smack in the faces of its users. The two companies are also working to add support so that developers can write HTML5 apps for the phone. “Our mobile strategy is simple: We think every mobile device is better if it is deeply social,” a Facebook spokesperson told AllThingsD, declining to comment specifically on the secret phone. “We’re working across the entire mobile industry; with operators, hardware manufacturers, OS providers, and application developers to bring powerful social experiences to more people around the world.” Facebook has repeatedly denied any interest in creating an own-brand device and the spokesperson’s quote is on a par with what the company has said in the past.