Time to take a break from Angry Birds and make your phone do something actually useful.  Check out these must-have back to school apps! Click on the android or iphone icon to go to the app preview page for download. All apps are free unless marked with a dollar sign.

Books

Chegg
Rent your textbooks and save money!

RedLaser  
A free scanning application with multiple uses, including locating a copy of a book in a nearby library (powered by WorldCat).

BookSearch
Search for online prices of books using an ISBN number, the book title, an author or keyword. It also allows you to purchase your book from an online retailer directly on your phone.

aldiko  
An ebook reader that lets you seamlessly browse and download thousands of books directly to your android device. Supports many file formats.

Bluefire Reader 
Compatible with ePub and PDF content, including ebooks from most online book stores and leading libraries.

Library resources

ACS Mobile
Provides you with a live stream of new research published by the American Chemical Society.

American Institure of Physics
Read AIP article content offline and store articles locally.

Annual Reviews Mobile
Once authenticated through the app, you can browse, search, and read full-text content anytime, anywhere on the Annual Reviews Mobile website.

arXiv 
Lets you browse e-prints by archive and subject category, as well as search for e-prints by title, author, abstract text, arXiv iD, or all fields. Once you locate an e-print, you can view its abstract and metadata or scroll through the PDF file.

EBSCOhost
Search any EBSCO database right from your iphone. To use this app, access EBSCOhost as you typically would via the library website. Click the link at the bottom of any EBSCOhost page to email yourself the key to the app.

Nature.com
View abstracts and free articles from Nature titles. Allows for search of Nature, PubMed, or arXiv. Links to full-text when available.

PLoS Medicine
Provides access to the Public Library of Science: Medicine, an open-access journal.

PNAS
Accesses PNAS content, the official journal of the US National Academy of Sciences, containing original research that broadly spans the biological, physical, and social sciences.

Sciverse ScienceDirect
Access the same journals and books from your phone as you would your computer.

SciVerse Scopus Alerts 
Find articles, create alerts, make notes, and share links instantly. Make sure you’ve registered for a username and password at www.scopus.com and use your institutional email address to sign in.

WorldCat
Use your phone to find materials in libraries near you.

Math

Formulas Lite 
A collection of important formulas of maths, physics & chemistry.

Formulus Free
Important formulas and topics for students taking Calculus and Differential Equations.

Grapher 
a simple graphing calculator with graphing capabilities similar to TI-83 or TI-89 calculators.

Math Ref Free
Over 700 equations, examples and tips to help you with math and science (paid version also available).

Quick Graph
A graphic calculator that takes full advantage of the multitouch display  of the iPad and iPhone.

Wolfram Course Assistant 
A collection of apps designed specifically for math and science courses.

Organization

myHomework
Track your classes, homework and projects so you never forget an assignment again.

iStudiez    
Manage your schedule, homework and grades. Color coded scheduling and cloud sync make staying organized easy (free lite version also available).

dropbox  
Bring all your photos, docs, and videos with you anywhere. After you install Dropbox on your computer, any file you save to your Dropbox will automatically save to all your computers, your phone and even the Dropbox website