What apps do consumers spend the most time with? The obvious choices are games, utilities and productivity tools, but according to San Francisco-based Crunchyroll, it may be time to add streaming TV to that list.

The video-on-demand service, which allows consumers to stream popular Asian TV dramas and animated shows to a variety of platforms including iOS, Android, Windows Phone and the Kindle Fire, is seeing its mobile usage soar. According to CEO and founder Kun Gao, while mainstream video streaming services like Hulu and Netflix report about two to three percent of their userbase streaming content to their mobile devices, Crunchyroll sees 10 times the amount of mobile usage.

Crunchyroll’s users –which tend to skew younger than those of Netflix or Hulu — are also more engaged on mobile, spending two to three times longer on a mobile sessions than they do on web-based ones.

“On the web we’re seeing on average 25, 35 minute sessions. On phones and the tablets we’re talking about an hour to and hour and a half on average,” he says. “It basically means for youth today, the phone is their primary form of entertainment, not necessarily the big screen or PC. It’s more personal, it’s a much more engaging experience.”

Crunchyroll has more than 8 million registered users, and while the company doesn’t share specifics about its mobile footprint, Gao tells us his company sees tens of millions of access from mobile devices every month, and that usage is accelerating.

“In terms of PC versus all other devices, we crossed over 50 percent maybe over 6 months ago,” he says. “It’s definitely indicating that the future of entertainment is going to whatever device the user is using, not one particular device or on a website.”

Interestingly, Crunchroll’s mobile users also show a higher free-to-paid conversion rate than those who come from the web. Gao credits this to the growing level of comfort consumers have show for paying for things on their mobile phones, and to the company’s business model. While its free to watch Crunchyroll programming over Wi-fi, he explains, if a user wants to watch over 3G, they will need to shell out for a subscription. “Mobile gives us a lot more opportunity to provide an experience that users are willing to pay for,” Gao says.