Useful apps for school

Technology is very useful these days, specially for school and education. Here are my favorite apps for school:

• Khan Academy: this is an app were you can see videos of I think every course like math, chemistry, physics or even economics and arts. The videos are short classes were somebody explains different topics in a very easy way. 
• OneNote:  is an app from Microsoft I use to take notes in classes. It is very useful because it has a lot of editing options so you can write and organize as you want. Another good thing about this app is that you can have different notebooks and it is free.
• iBooks: I use this app from Apple to save my PDFs files. You can save as much as your memory holds. Also you can export them to your computer or send it to other apps.
• Tiny scan: this app alouds you to scan you notebook notes and transform them into PDFs files.
• Calculator: it can make every math operation and also solve equations giving you the information that is missing.