StudyBlue, an edtech launched by Wisconsin University alumni in 2007, has raised $1.7m in a venture round. Investors are Great Oaks Venture Capital, the Wisconsin Alumni Research Foundation and StudyBlue chairman Steve Wallman, a securities analyst with Wallman Investment Counsel.

The edtech has now raised $17.1m from outside investors. Its $9.3m series A in 2013 was Wisconsin second-largest venture capital raise of the year.

The startup has created educational web and mobile apps that give students access to a shared library of more than 220 million user-created study documents. The documents can be stored and accessed across devices, and can contain notes, flashcards, and equations that can be complemented with images and audio. The software also lets students and teachers collaborate on documents. Available subjects cover a broad range from chemistry to calculus to Chinese.

StudyBlue, which counts some 5.5 million users, originally focused on university students, but has since extended its offering to students in primary and secondary education. The company operates on a freemium business model, which offers premium subscriptions and free access supported by advertising.

Becky Splitt, chief executive at StudyBlue, said: “In the past year, StudyBlue has seen phenomenal growth, attracting more than one million new users, in part because we now house the largest collection of user-generated content of its kind. This growth signals a need for richer digital learning tools – a need that StudyBlue will continue to meet, and this latest round of capital helps us do that.”