Trustudy is an app that allow to students study together sharing lecture notes, questions and answer.
With Trustudy, students can complement the class with classmates's lecture notes. In this way there are more ways to learn, this is in a collaborative enviroment.
In Trustudy you can create a notebook for each course for free but if you want privacy (choose who can see yours notebooks) you can pay for it. Then you can sell your lecture notes, resumes or any study material to another classmates.
If you have a free account all of your material is free for your classmates that can make improves the quality of the material, can ask and answer questions and finally make the study time online more productive.