Concept mapping

Concept Mapping: Textbook App
I had first started out with the idea of trying to fix the unemployment problem in America but there weren't many solid, sure solutions for everything. So instead, I thought up something else: The Textbook App.
Being in the 10th grade in high school, its annoying to carry all of these heavy textbooks across campus 5 times a day, to home, and to school again. We have about 4-5 textbooks per student that weigh around 3 pounds each. if we're carrying about 2 to 3 textbooks around campus, that's around 6 to 9 pounds of just textbooks. We aren't accounting for the weight in our backpacks from the notebooks, workbooks, binders, and other supplies. All of that weight on your shoulders all day, everyday creates a lot of stress and pain in our shoulders.
Now let's consider college. Buying textbooks can get up from $1000-$3000 per year. Buying used textbooks are normally already marked up and scribbled on by other students and it looks messy.
Other problems would fall under how we can't make marks in our textbooks, pages start to fall out of the textbook, and they're hard to store at home due to how big and bulky they are.
Online textbooks are offered, but the websites are messy, some devices aren't compatible with the website, and you can't make notes on the online page.

 My idea was to make a textbook app that was much more cheaper and convenient for the everyday student. On the app you could access textbooks for free or for a very low price on any and every device. The layout of the app would be simple and you can do things like make marks and notes without cluttering the page.