Open up Gallery on your phone and count how many images of your or someone else's notebooks you have. I have dozens, and only because I delete them after they stop being useful. For that reason I have created Notekeeper - an easy way to share all school-related material among your peers.
Apart from notes which are organized into courses and lessons, you can also share questions and exam schedule. And the best of all is that data never stops being useful - you can hide stuff you're not currently interested in, but all the items will remain for your younger schoolmates. Spend one last year taking notes, and after that only improve others' work.
Along with notes, you can also store questions in order to refresh your and your peers' memory or provide examples for the exam
Your school or college is represented by one large group, where everyone can add or edit content. For the ease of browsing, it's split up into courses, identified by subject, teacher and year, which are further divided into lessons. You can hide them at any time (as well as re-show them), or filter out years you're not interested in.
You can attach an image to any note or question, or upload a note with an audio recording, if you prefer it to writing out everything. All images are stored on the server, and downloaded in full size (max. 2580px wide).
All data is also stored on your device, so that you can browse everything while you're not connected to the internet. Images are on your sdcard, under DCIM/Notekeeper, and recordings in recordings/Notekeeper, if you ever need to take a look at them
All content, except items associated with exams and audio recordings, is accessible to everyone. Interested in what people from other schools do? Look them up! What do lessons look like on your desired college? No problem! (You just need to make them download the app)
At the moment, only way to access the network is through the Android app, but web platform is in the works (interested? If you're a programmer, there's a REST API you might find useful, contact me)