Pearltrees is a free, visual and collaborative library that lets you keep everything you like at your fingertips. Its unique interface lets you organize and retrieve your favorite web pages, photos, and notes -- even offline. You can also leverage Pearltrees' community members to discover amazing stuff related directly to your interests. Enrich your account with those you like best. With Pearltrees, you can cultivate your interests wherever you are.
I have spent some time and gone through this application. This application reminds me a little bit like Pinterest. This can collect all things you find interesting on the internet. It allows you to organize them into "pearls" that stack like a mind map. Students can use this tool to create online portfolios. They can upload files as well as type text or bookmark websites. Their ideas can be organized in any way they see fit.
The price is right for this app. Free. There are paid plans that give you more options but you get plenty for free.