Messaging apps have become the de facto way that many people today keep in regular contact with each other, and that trend has also found its way into the classroom. ClassDojo, a startup that has built a platform for teachers and parents to communicate small and big updates to each other, today is announcing that it has raised $35 million in funding.

The Series C — which is being jointly led by GSV (behind Spotify, Lyft, Dropbox) and SignalFire (which has backed Grammarly, Zume, Lime), and also includes General Catalyst and Uncork Capital — will be used in two ways. First, to fuel expansion of ClassDojo’s free communications app. And second, to drive its efforts to monetize its service by way of a new service called Beyond School, an optional subscription for families to complement in-school work with at-home tutorials around areas that are complementary to learning well, such as improving studying habits, mindfulness and so on.

(You could think of Beyond School as TedX meets Lynda for K-8, but co-founders Sam Chaudhary and Liam Don, respectively the CEO and CTO, said in an interview that they believe the content will be more than just that.)

ClassDojo has now raised $65 million, and while it is not talking valuation, I’ve been told by a good source that it is coming in at “$400ish” million. That is a huge leap on the $99 million the startup was valued at in 2015 (a figure quoted on PitchBook).

The boost in part is because of ClassDojo’s healthy growth. Since first starting out in 2011 as part of a Y Combinator cohort, the company has expanded to be used in more than 95 percent of all pre K to eighth grade schools in the US, with one in every six families with a child in primary school using the app daily.

The US is its biggest market, but ClassDojo is also now available in some 180 other countries, where it’s also starting to pick up some strong penetration. (In Singapore, Australia, Spain, Hong Kong, the UK, and the UAE, it’s used by some 25 percent of all primary school teachers, for example.) Impressively, all that growth has up to now been organic and word of mouth, one reason why the company has had to raise relatively little funding.

(It also only employs 40 people, another way of keeping costs massively down.)

One of the key things about ClassDojo is that the company has kept a very consistent focus when it comes to its mission: the idea has always been to try to identify the biggest communication problems that teachers might have in teaching kids, and trying to solve them.

Building an app that can bridge the sometimes large gaps between parent-teacher meetings, so that parents feel more engaged with what their children are learning, and teachers might have better feedback from those parents about what children are doing at home, was an obvious first step.

“Learning is so much about having strong relationships,” Chaudhary said. “It’s pretty cool to see the effect this can have not just with parents and teachers, but between parents and kids.”

Beyond School comes in the same vein and is a natural extension of that, and came not just out of what teachers said they wished they had more time to teach to students — but can’t because of the general emphasis in curriculums on academics — but from what parents wished they could work on with their children.

That, in essence, is the wider body of “learning” that you could loosely term emotional intelligence, and general techniques for coping and learning, beyond the academic work itself. “The learning experience in the classroom sparked a lot of ideas, and families were reaching out to us,” Dom said, “wondering if they could have a product to serve more unique needs at home.”

So far, the company does not have any numbers to share on how Beyond School has been taken up since launching at the end of 2018, except to say that it’s going well.

Longer term, it’s interesting to consider how ClassDojo fits into the wider trend of communication and messaging apps, and whether others might ever try to compete in the same space, or perhaps acquire ClassDojo as they extend into other verticals — a strategy that Microsoft, for example, has been following when it comes to acquiring other businesses as it works on tapping the $10 trillion market for education.

I asked Hemant Taneja, a partner at General Catalyst, if he ever thought the likes of Slack, for example, might ever try to compete with it. (No, is the short answer.)

“Slack is a work tool, and I can’t imagine there will be a synergy there,” he said, and nor would it possibly even work. “As a worker and parent, I think that there should be an education platform solely devoted to kids, where the stakeholders are family and teachers. I’ve always believed that from the beginning and I think that ClassDojo’s scale gives it that potential.”