Some new details have emerged about Jelly, the mysterious startup from Twitter co-founder Biz Stone: The company's app is "very close" to launching, and will be available for free on iOS and Android-based devices, Stone recently said. "Jelly is starting to come to life," said Stone, the co-founder and CEO of the new company, in a blog post on Tuesday. The Jelly mobile app, he said, is "very close to launching."