Fantasy sports app Draft is predicting a big score with mobile users, and it cranks up tonight with the NFL's season opener.

The New York-based startup founded in December is launching its betting-enabled daily fantasy app on Android today, along with a 2.0 version of its existing iPhone app. The free apps let users participate in daily fantasy sports--a form of fantasy that condenses a season into a single day or week--for a 10 percent cut of the money wagered. The process is legal because Draft is a game of skill in which users are not betting on the outcome of individual games, as in traditional gambling.

Backed with $3.5 million in funding from venture firms including Upfront Ventures and David Tisch's BoxGroup, Draft hopes to become the go-to company for mobile-first fantasy betting. "No one has ever built a mobile game for fantasy sports," says Draft co-founder Jeremy Levine. Though fantasy behemoths FanDuel and DraftKings--both of which are valued at more than $1 billion--account for roughly 95 percent of daily fantasy players, Levine says his target users are not existing daily fantasy players.

"Essentially, what we've built is Words With Friends for fantasy," he says. "Instead of making a word, you're picking a player." Like multiplayer crossword game Words With Friends, Draft uses a turn-based system where users go back and forth drafting fantasy athletes. The simplicity of the game is part of what Levine thinks will attract users who consider regular fantasy sports to be too time-consuming.

"With season-long fantasy, you need to join a league, set aside a whole night to draft a team, and you have to commit to managing that team for an entire season," Levine says. "That is not how we play mobile games." Though Draft has competition from services like DailyMVP and Sports Lock, Levine says both have very different user experiences that don't share Draft's focus on simplicity.

It's worth noting that Draft is not Levine's first startup in the fantasy industry. Prior to launching the company, he and his co-founder, Nicolo Giorgi, sold their Techstars-incubated "sports stock market" company StarStreet to DraftKings for an undisclosed sum. Though Levine declined to disclose revenue or user data for Draft, he says the app attracted more users in its first eight months than StarStreet did in five years.

"Our market is truly every sports fan in America, and that is about 250 million people," he says. In addition to NFL games, Draft allows users to bet on college football, the NHL, NBA and college basketball. Each bet can be as small as $1 and as high as $50. The 11-person company plans to add fantasy golf in 2016.

With the start of the NFL season on Thursday, Levine says Draft could double its user base by the end of September. While that might sound ambitious, so far Draft has been gaining traction with various types of first-time fantasy players, according to Levine.

"We're certainly a lot of people's first time playing with real money," he says. "We're also a lot of people's first time playing fantasy sports."