When it comes to studying, the iPhone or Android can be turned into a useful learning tool just by downloading a few apps. MindMeister.com mapped out the top 100 apps by category for high school and college-age students. Here are some favorites:
MATH
The Graphing Calculator app ($1.99) will help math whizzes double-check their homework. With the app, students can graph multiple equations, export graphs as e-mails and find the exact coordinates for roots, intersections or minimums and maximums by using the trace mode (yeah, I've got no idea what that means). Graphing Calculator is available for the iPhone and iPad, and Time magazine names it as one of its top 10 back-to-school apps.
You might already be familiar with WolframAlpha.com ($1.99 for iPhone, $3.99 for Android), which is like Google for geeks. Ask it computational questions like, "How many calories are in a bagel?" (207.) Or "How many moons does Mars have?" (Two.) The company has a snazzy app that does all this and even more. You can compute momentum or use Ohm's law calculator (this calculates electrical relationships between resistance, current, power, voltage and other things I don't understand).
SCIENCE
Redfox's Periodic Table of Elements is free for iPhone and Android and will be of great help to any chemistry student, who can access information for 117 different elements with the click of a button. For instance, helium is a period 1 element in group 18 under the noble gas category. (Um, OK.) In addition to getting the atomic number, family name and chemical symbol for each element, the app retrieves data from a wiki that'll dive further into the element's chemistry.
SageMilk's College Biology, Biochemistry and Human Physiology (free) for iPhone and iPad and 1,000 Biology Terms & Quiz ($1.89) for Android help students focus on learning the complicated aspects of bioscience. The apps walk users through basic biology terms presented in a way similar to "Jeopardy" (though you don't have to phrase your answer like a question). Serving as a great study aid, these programs let you create custom flashcards and multiple-choice and true/false quizzes.
ENGLISH
To be or not to be, that is the question. Actually, to download or not to download -- well, there's no question that you should download the totally free Shakespeare app (alas, it's only for the iPad and iPhone). It has the complete works of the Bard locked and loaded for easy reference and includes scene breakdowns to give English students a refresher course on what happened (think of them like recaps, except for really good literature instead of TV shows). There's a search function as well as a limited Shakespearean glossary and famous quotes section. (You can also get Shakespeare Pro for $9.99.)
ORGANIZATION
With course loads getting heavier, it's getting harder to keep track of what homework is due when. Enter Wunderlist, a free task manager for the iPhone and Android that has gotten rave reviews. It's easy to use and also has a website that can be accessed from a computer for easy adding and subtracting of due dates and to-do lists. The website syncs with the app and vice versa.