On April 1st, Twitter co-founder Biz Stone posed a question on a company blog: "What is Jelly?" The answer, he said, is a new company and product named after the jellyfish. Unmentioned in the post is that Jelly is the second jellyfish-themed product with which Stone has been associated. Before Jelly, Stone advised a lesser-known Q&A startup named Fluther. A fluther — it rhymes with "brother" — refers to a group of jellyfish. If you want to know where Jelly is heading, Fluther is the place to start.

Jelly plans to take core ideas from Fluther and remake them in an app purpose-built for mobile devices, according to a person familiar with the company's plans. Fluther, whose team was acquired by Twitter in 2010 but remains operational, is part of a crop of web-based knowledge platforms that sprung up toward the end of the last decade. Quora, ChaCha, and Aardvark are among the companies who raised millions of dollars on the premise that high-quality, real-time answers represent the logical evolution of search engines. (Google bought Aardvark for $50 million and promptly shut it down.)

Fluther's take on Q&A involves using algorithms to route personalized questions to users based on their expertise. It is designed to be used in real time, so that "each question feels like its own chat room." In a Twitter-like touch, users follow a "fluther" of interesting people to help personalize the questions and answers they receive. Meanwhile, a team of volunteer moderators tries to prevent the site from devolving into a Yahoo Answers-style wasteland; providing high-quality answers helps you increase your "lurve" score.

It remains unclear how Jelly will work, or whether it will have any connection to the existing Fluther service. The person familiar with Jelly's plans said it was strongly related to Fluther but did not see the product itself, which is still early in its development. The Jelly team is trying out a range of different approaches, the person said.

If Jelly has more mystique than most Silicon Valley startups in stealth mode, Stone is the major reason why. After getting his first job designing book covers for Little, Brown and Co., he became creative director at Xanga Inc., the early social network and reviews community. From there he had prominent roles at Google, which he joined after it acquired Blogger, and at Twitter, which he co-founded with Jack Dorsey and Evan Williams.

In 2009, Stone became an adviser to Fluther, which was founded by Ben Finkel and Andrew McClain in the summer of 2007. By the time Stone joined, it was attracting more than half a million monthly visitors and raised $600,000 from prominent Silicon Valley investors including Ron Conway, Naval Ravikant, Marc Andreessen, Ben Horowitz, and Dave McClure. In a screencast to accompany the news, co-founder McClain said that 98 percent of questions on Fluther get answered, with an average of 14 answers apiece.

Barely more than a year later, in December of 2010, Twitter acquired the team behind Fluther for an undisclosed sum. Four engineers and a designer came on board, Finkel and McClain included. At that point, active development on the website stopped, and it was handed over to community manager Lisa Noll, who continues working on Fluther. Finkel and McClain have continued to oversee the site.

Stone had stepped away from day-to-day duties at Twitter, so he didn't work with the Fluther team once they arrived. Finkel was put in charge of new user experience on the growth team; while he was there, Stone notes, Twitter grew from 50 million active users to 200 million active users. Finkel quit in March; on his last day, co-workers carried him out of the office. A few weeks later, Stone revealed Finkel would be Jelly's chief technical officer.

Even a cursory glance at Fluther's website reveals connections between Finkel's old company and his new one: Each employs the jellyfish as a logo. Each emphasizes the power of groups, connections, and the ability to do good. Then there's the name Fluther gives its users: "jellies." "Knowledge diversity is something we prize highly and is also something that will be represented in our product," Stone has said of Jelly — something that is also true of Fluther, and fits with the notion of a crowdsourced information platform.

There is no shortage of question-and-answer services online, but most of them were built first for the web. Quora, the most highly valued service of the current crop, launched in beta in January 2010 but didn't release a mobile app until September 2011. The mobile app has lagged behind the website in features; Quora only added a search function to the app last month.

ChaCha has put more emphasis on mobile search, letting users send in questions via text message as well as mobile apps, but the quality of its answers varies widely. The most profitable and widely used Q&A platform in the world remains Google, which has begun placing more emphasis on letting users ask questions using natural language and receive immediate, high-quality answers.

Since announcing Finkel's hiring, Stone has been building out his team. In recent weeks he has scooped up Kevin Thau, who formerly ran mobile efforts at Twitter and had most recently built the #Music app, and added Tweetie and Letterpress creator Loren Brichter as an adviser.

In April, Stone said of Jelly: "it won't be ready for a while." In an email to The Verge, he declined to comment on the company's plans. But for all the mystery surrounding Jelly's development, its basic direction may have been hiding in plain sight. The company, Stone has said of his and Finkel's brainchild, is "the idea that we couldn't get out of our heads."