Competing in the crowded streaming market for children’s content with the likes of Netflix and Amazon is never easy, but through differentiation and increased investment in originals, Houghton Mifflin Harcourt’s SVOD learning app Curious World is quickly making a name for itself.

Last October, the year-old SVOD surpassed one million iOS downloads in the US. It’s driven by a focused lineup of original and licensed short-form videos, eight key learning areas, and a diverse portfolio of 150 original games and eBooks curated by early learning experts.

In total, the platform offers more than 1,200 pieces of content, including more than 60 original kids series for US$7.99 a month. Among its originals are HMH series Curious George, music series A Rhino Named Paul, language-learning program Jingle Bilingual, how-to costume series Recycled Superheroes and live-action arts & crafts program Get Crafty.

More recently, Curious World debuted its original animated series Mac & Izzy, a co-pro with UK-based Blue-Zoo Productions and US public broadcaster WGBH Boston that originally launched on the YouTube Kids app in November.

And just last month, the platform debuted Through the Woods, an original 2D-animated nature-inspired series made in partnership with The Fred Rogers Company. The series marks The Fred Rogers Company’s first foray into original programming for mobile devices.

Curious World also just launched a new original STEAM-focused series from the creators of Peg + Cat entitled Melia and Jo.

On the third-party front, Curious World series include Disney Sound’s They Might Be Giants, JibJab’s StoryBots and Skyship Entertainment’s Super Simple Songs, as well as titles from National Geographic, Caspar Babypants, PBS Digital Studios, Radical Sheep and Young Rembrandts.

For CJ Kettler, EVP and chief of consumer brands and strategy at HMH, the Curious World team has learned an enormous amount about its audience and what they’re looking for.

“We’re now looking at metrics that are over a year old for those that came on very early, so it’s exciting to see some of those subscribers rolling over,” says Kettler. “Our eight key learning areas make us different for parents in that they provide a feedback route to determine if their kids are drawn to subjects like science, math or literacy.”

She adds that another key differentiator is the app’s variety of arts & crafts shows that encourage real-world creativity and activity. “Because of our focus on kid engagement and learning areas, we’re pretty unusual in that we let our content drive kids offline to make things, unlike other digital services that try to keep kids in episode after episode looking for the longest running time,” she says.

Further supporting offline usage and physical activity, Curious World launched a successful campaign in December that packaged subscriptions with kindergarten-readiness boxes that each included a Curious George book, an activity book, and a game all tied to a particular learning area.

As for its ties to the larger web, Curious World uses its own YouTube channel to promote the brand. But according to Kettler, it’s very careful in just providing content teasers that don’t diminish the value of the full Curious World subscription.

Games are also very important to the platform, she says. “In terms of media format, games are our strongest driver, then videos, then eBooks. We also find that what kids use by platform is a little bit different,” notes Kettler. “eBooks are not the most widely used on phones, but on Apple TV it’s the opposite. When we tested on Apple TV, we realized that the eBook experience, to some extent, was an entirely new experience for families.”

Going forward, Curious World is entertaining the idea of producing original long-form series, but with partners and not necessarily for its own platform. It’s also actively talking to potential partners on a territory-by-territory basis to take the app beyond the US and the iOS operating system.