It’s back to school laptop-buying season, and I would guess that more than a few of you will be picking up a shiny new Apple laptop to tote between classes. This summer, Apple is giving away a $100 iTunes gift card to any students purchasing a new Mac, and while some are bummed out that it isn’t an iPod like in years past, the brand new Mac App Store at least gives you a great place to spend that free money.

With that in mind, here’s a list of $99.93 worth of great apps that any Mac should have. Prices are accurate as of 7/23/11, but are subject to change.

Keynote ($19.99)

If you’re going to buy one app from the iWork suite, make it Keynote. I’m consistently blown away by the quality of presentations that the average student can turn out with this program, and you need look no further than any Apple product announcement for a great example of what Keynote’s capabilities. Magic Move allows for animated slide transitions that won’t make your classmates groan, and the automatic spacing guides lets you snap text boxes and images into the most aesthetically-pleasing spot of the presentation. It is cheaper (and in my opinion better) than Powerpoint, and offers far more features than the presentations app on Google Docs. Plus, it’s free money, so why not. 

Pixelmator ($29.99)

The priciest app on this list, you’ll really only need to pick this up if you don’t already have some version of Photoshop (and in fact, Photoshop Express just appeared in the App Store, albeit for $80). Pixelmator is an attractive, semi-powerful image editor designed with Mac users in mind. While I might have recommended the free and open-source GIMP before, OS X Lion doesn’t include the X11 software necessary to run it, so you’ll probably need to spend a few bucks for anything beyond very basic image editing. Pixelmator includes full layers support, advanced color correction, and a number of tools that should be familiar to anyone who’s ever used Photoshop. 

Window Magnet ($4.99)

By far my favorite feature of Windows 7 that isn’t replicated out of the box with OS X is the snap-in-place ease of window management. Drag a window to the top of the screen to maximize it. Drag it to the left or right to fill half the screen. Given that the little green button on a Mac window does everything except what you’d expect it to, apps like Window Magnet that replicate this behavior are much appreciated. Though it competes with similar apps like Cinch, Divvy, and Flexiglass, Window Magnet offers the best combination of price and flexibility.

Schoolhouse ($4.99)

You could spend an inordinate amount of money on a Getting Things Done app like Things, or you could dip your toes in the GTD world with a student-developed app like Schoolhouse for the price of a good beer. Schoolhouse helps you keep track of your classes, assignments, and grades through a variety of customizable views and inputs that can conform to your needs. An app like this isn’t necessary for everyone, but if you put in the time to incorporate it into your workflow, it will almost certainly pay dividends. 

Fantastical ($19.99)

Between clubs, internships, and classes, college can fill up your calendar in a hurry. Fantastical (emphasis on “cal”) makes it easier to update and check your iCal calendar in a hurry. The app exists as a small button in your menubar, and gives you full dropdown access to a daily planner. It also adds natural language event recognition, something Google Calendar users have enjoyed for years. For example, “Dinner with Bob Friday at 8″ adds an event to your calendar automatically, rather than forcing you to fiddle with a bunch of dials. 

Reeder ($9.99)

Reeder is, beyond any shadow of a doubt, the best Google Reader client on the App Store. You may be familiar with the excellent iPhone and iPad versions that started it all, and the desktop version doesn’t disappoint. You can navigate the beautiful interface with keyboard shortcuts and multitouch gestures, and send your articles to any number of other services with a click of the mouse. It can be tough to digest all of the information coming in from your favorite feeds each day, but Reeder makes the process as pleasant as it could possibly be. 

DaisyDisk ($9.99)

If you have your Mac long enough, it will eventually be time to clean up your hard drive. This is doubly true if you opted for a MacBook Air with its comparatively small solid state drives. DaisyDisk presents you with a beautiful, color-coded chart to help identify the hidden files and folders that are eating up your space. The idea isn’t revolutionary (OmniDiskSweeper does it for free), but it presents the data far more beautifully than any other product. You could do a lot worse with your final $10.