Houghton Mifflin Harcourt, the global learning and publishing company behind Carmen Sandiego and Curious George, is making further strides in the early education space with the launch of an interactive subscription service entitled Curious World.

Aimed at kids ages three to seven, the iOS app offers games, videos and eBooks, all of which will feature HMH classic properties like Curious George and Gossie and The Polar Express, as well as original exclusive games. Acquired content will hail from a range of partners, including National Geographic Kids, StoryBots and PBS Digital.

The customized content on Curious World will be curated by early childhood experts and is aligned with eight key learning areas: Science, math, language and literacy, health and wellness, creative expression, social and emotional development, executive function, and family and community.

At launch, Curious World will contain more than 500 unique titles, with new content added to the service on a weekly basis. More content is expected to arrive in the coming weeks and months, including original HMH videos and games, additional partner content and eBooks.

The app can be downloaded for free from the App Store with a limited sample of content and basic features, while access to the full customized content is available for US$9.99 per month or US$79.99 per year.

There’s also an accompanying parental dashboard that provides tips for balancing kids’ screen time endeavors with offline learning activities.

The service is launching into a market that’s continuously being shaped by preschool video consumption, as well as by video-educational gaming platforms like PlayKids and Hopster. In fact, currently within the US, three of the five top-grossing children’s iPhone apps for kids under the age of five are video players.