Flipgrid — which makes a video-sharing platform for students and educators — is getting a big boost and a worldwide audience after being acquired by Microsoft.

University of Minnesota Prof. Charlie Miller designed the system in 2012 to communicate with his students. It allows students to post videos on a grid similar to a Pinterest page around a topic posed by an educator or student.

"We're thrilled to see the impact Flipgrid has had in social learning thus far and look forward to helping them continue to thrive as part of the Microsoft family," said Eran Megiddo, corporate vice president for Microsoft. "We're diligently committed to making sure their platform and products continue to work across the Microsoft, Google and partner ecosystems to benefit students and teachers everywhere."

As part of the announcement, Redmond, Wash.-based Microsoft said it will make Flipgrid, which used to have a free and premium business model, available for free to all educators, and Microsoft will make a refund to educators who upgraded to a pay model in the past year.

"This opportunity not only makes Flipgrid free to every educator, we get to partner with a global network that is already partnering with educators around the world," said Joey Taralson, Flipgrid's vice president of engagement.

Miller co-founded the company in 2015 with CEO Jim Leslie and Phil Soran, a company director, when they acquired the rights to the Flipgrid technology from the U's College of Education for $6.75 million. The college maintained a 4 percent equity stake. The company immediately raised $17 million of equity seed capital to fund the growth of the platform.

Users now include 20 million educators, their students and families in 180 countries.

Flipgrid's 25-person team, including Miller and Leslie, will remain with the unit and will become part of the Microsoft Education team led by Megiddo. The unit, which will remain in Minneapolis, will continue to add new capabilities and features based on user feedback.

"Our No. 1 role is to listen to educators in the community," Taralson said.

The partnership also gives Flipgrid access to Microsoft's data security tools that will enable Flipgrid to continue its rapid growth and ensure its platform remains a safe and secure place for students and teachers to communicate.

Flipgrid plans to announce upgrades to its platform at its annual educator conference Aug. 1 in Minneapolis.

Terms of the transaction were not announced.