Brothers Brett and David Kopf launched Remind101 out of Imagine K12 in late 2011 to tackle what they saw as one of the key problems in primary education: The lack of simple, user-friendly tools that help teachers better communicate with both students — and their parental units. Today, in spite of how critical effective communication is within the K-12 learning equation, schools continue to rely on intercoms, PA systems, paper-based permission slips and phone trees. In other words, the same tools they’ve used for 50 years.

Remind101 released mobile apps for Android and iOS last year to help bridge that communication gap, creating a mobile platform that enables teachers to send reminders to students and parents via text and email — be they about permission slips or deadlines — and that acts as a secure, private communications network. The app caught on quickly among teachers and the demand hasn’t slowed down since.

By September of last year, Remind101 had six million teacher, student and parent users, a number which today has grown to 10 million, and over 65 million messages are being sent via the Remind101 platform each month. The 10 million user number puts the startup in exclusive company in the education technology world — a fact which has not gone unnoticed by investors.

That’s why today, a little over four months after it closed $3.5 million in series A financing from Social + Capital, Yuri Milner, Maneesh Arora and a handful of angel investors, Remind101 is adding another lump of coin to its coffers.

Today, the startup announced that it has closed a $15 million Series B round, led by Kleiner Perkins Caulfield & Byers, with additional participation from its previous investors, including Social + Capital and First Round Capital. As a result of the round, Kleiner partner and veteran investor John Doerr will be joining the startup’s board of directors, alongside Social + Capital founder, Chamath Palihapitiya, who joined the board as part of Remind101’s Series A investment.

Although Kleiner Perkins has had its ups and downs of late, adding a veteran investor like Doerr is a big win for the two-year-old startup. While his own investment record, as we’ve noted before, isn’t perfect, there’s a reason that Google co-founder and CEO Larry Page has been quoted as saying that Doerr “sees the future first.”

Doerr has been a Kleiner partner since 1980, and has backed companies like Netscape, Sun Microsystems, Intuit, Amazon, Google, Twitter and Symantec. In more recent years, he’s also become a vocal supporter and evangelist for innovation, and reform in education, among other spaces. Remind101 is now one of two education companies to count Doerr as a board member, the other being Coursera, and, although an evangelist for innovation in education, one of only a handful of educational investments Doerr has made, Coursera and Dreambox Learning included.

When we asked the Kleiner Perkins Partner why he chose to lead the firm’s investment in Remind101, he answered, simply, that “all the studies have shown that when you get teachers, parents and students communicating more regularly, you get better learning outcomes.” Doerr is alluding to the long-held (and now data-backed) belief that students are more likely to succeed, to graduate and to learn more effectively with more involvement at home and with parents that are actively involved in their student’s educational career.

While this can be difficult for many families to attain, both Doerr and the Remind101 founders believe that the first step is to reduce the barriers, or make it easy, for parents and teachers to bridge that communication gap and encourage a more regular dialogue between each party.

Traditionally, education startups have had to work within the system to sell into K-12 schools; in other words, the sales process, and adoption, tends to only work (or at least be most lucrative) at the district and state levels. Of course, winning district or state contracts takes time, effort and dealing with the headache of a bureaucratic approval process. So, the other appeal then of Remind101, Doerr says, is that the startup doesn’t have to get approval from institutions to operate within their schools, nor do they have to get districts to sanction its usage.

Instead, Remind101 can sell (although this is somewhat misleading since the platform is free to use) directly to teachers. Not only that, but as Remind101’s adoption and penetration increase, Doerr sees the potential for the platform to become the access point to up-sell teachers and schools to additional, premium features.

These might include the ability to sign paperwork via mobile devices, transmit and share permission slips, facilitate payments, transactions and other services, for example, all of which can be built on top of the platform. Not unlike, say, TigerText for K-12 education. Although the platform is free to use for teachers, and the Kopfs tell us that they plan to keep it that way for the foreseeable future, that’s how Remind101 could begin to monetize down the road.

However, with its new funding under its belt, the Remind101 founders plan to ramp up hiring and product development, doubling its current team of 15 over the next year, with a particular focus on adding to its sales and business development teams. On the product side, as mentioned, the Kopfs plan to begin adding additional services to the platform in the coming months that will give teachers the ability to poll families for feedback and sign paperwork, for example.

“The reality,” says CEO Brett Kopf, “that teachers are overextended and struggle to give each student the individual attention they’d like, along with facing the nagging difficulty of finding the most effective channels to communicate with students — and their parents.”

While students today are tapped into an increasing number of digital and mobile networks and platforms, the common denominator continues to be mobile phones, as some 78 percent of teens age 12 to 17 have access to a phone. Furthermore, as anyone who’s come in contact with a teenager over the last year can attest, text messaging tends to be quickest and most effective way to communicate with teens, especially.

The Kopfs believe that they can leverage the growing pervasiveness and adoption of text messaging not only among students, but among parents as well, to allow teachers to motivate and remind students and parents about critical information. The goal, the CEO says, is to extend the classroom, while allowing teachers and parents to get set up in a few clicks, without requiring either side to download or manage an additional inbox.

In so doing, Remind101 has managed to extend its own bank account (and board experience) by at least a few degrees. Not to overstate things, but considering Remind101 has been able to add about one million users per month over the last four months, the startup has quickly become one of the fastest growing education technology startups out there and, if it’s able to maintain its current trajectory, it could be the next big K-12 education company, period.