“They’re solving problems like education and health care, creating jobs, and manufacturing right here in the U.S. And yes, a few of them also happen to be making some pretty cool apps for your phone.”

Below is the “30 Under 30″ of US business start-ups, published on Inc.com. You can also view the slideshow here.

Contently

Joe Coleman, Shane Snow, and Dave Goldberg founded Contently as a way for companies looking for great content to pair up with talented writers and journalists who could supply it. In an already disrupted media industry, they may be on to the new, new thing. Read more

Fabulous Coach

Ray Land turned his childhood love of big trucks into a booming business that shuttles more than 2,000 people on its fleet of more than 50 vehicles to cities like New York, Atlanta and Washington, D.C. Land is also creating a mega truck-stop off an abandoned interstate exit to be called, naturally, Fabulous, FL. Read more

Heyzap

Gamers Jude Gomila and Immad Akhund have been fast friends since age 13, when they started trudging their heavy desktop PCs over to each other’s houses in a northwest London suburb. Their wildly popular mobile app, Heyzap, downloaded by more than six million people, lets smartphone users check into games, discover new ones, and earn badges. Read more

PharmaSecure

In 2005, Nathan Sigworth started researching ways to fight counterfeit drugs after spending a summer volunteering at a hospital in Uttar Pradesh, India. Now, PharmaSecure makes software that produces unique serial numbers printed on each package of medication. Consumers can text the codes to a phone number on the bottle and verify that the medication is authentic. Read more

2tor

Jeremy Johnson is proving that universities can offer a quality experience online as well as on campus. 2tor has developed six graduate programs with top universities, including USC, UNC-Chapel Hill and Georgetown, and their job placement rates match those of their offline counterparts. That success has helped the company attract nearly $100 million in funding. Read more

University Parent Media

As a senior at the University of Colorado at Boulder, Sarah Schupp saw that colleges, families, and local businesses needed a way to communicate and make all of their lives easier. Her company, University Parent Media, produces print, Web, and mobile content that helps all three audiences stay in touch and informed. Read more

Tieks

Kfir and Elram Gavrieli had a big sister who hated wearing high heels on her commute but balked at clomping to work in sneakers. So the three siblings created Tieks, a high-end leather ballet flat that folds into a little pouch a woman can stash in her purse. Read more

Ciplex

Ilya Pozin found a sweet spot in the crowded Web design industry—small and mid-size businesses that want a great product that’s still affordable. Pozin says Ciplex, a full-service interactive marketing agency, takes on 20-30 projects a month and accepts only 7% of the customers who apply. Read more

Lookout Mobile Security

John Hering, James Burgess, and Kevin Mahaffey pulled a phone-hacking stunt at the Oscars to prove a point about the need for mobile security. Now, their key product, Lookout Mobile Security, protects the devices of some 20 million users from malware, spyware, and privacy breaches. The app, which works on both Androids and iPhones, also allows users to locate their lost or stolen devices. Read more

Jess3

Jesse Thomas and Leslie Bradshaw founded Jess3, a creative agency that specializes in social media strategy and data visualization. Setting out to make information less boring, the company uses techniques such as stop-motion animation, infographics, and puppetry (yes, puppetry) to produce viral campaigns and videos for clients that include Google and ESPN. Read more

GiveForward

Desiree Vargas Wrigley founded GiveForward to allow people to raise money for crushing medical expenses. Since its launch in August 2008, it has brokered nearly $11 million in donations. The family of freestyle skier Sarah Burke, who died in January after a training accident, raised more than $250,000 in one day through the site. Read more

AppStack

Steve Espinosa tested out of high school at age 16 to start working as a web designer. Now, Google Ventures and Eric Schmidt’s Tomorrow Ventures fund his company, AppStack, which makes an automated tool that quickly creates mobile websites for small businesses, and then uses Google advertising to drive traffic to them. Read more

Blank Label

Fan Bi and Danny Wong set out to create an edgy, artistic online custom shirt business. To their astonishment, they soon learned that the best customers of their brand, Blank Label, weren’t edgy young creatives, but rather 30-something professionals who used to shop at Brooks Brothers. The pair pulled off a neck-snapping pivot, and today the bootstrapped company has 20,000 (conservatively) well-dressed customers. Read more

Dwolla

At his fist startup, an e-commerce operation, Ben Milne got “really really pissed off about interchange fees.” So he did something about it by starting Dwolla, a cheap way to send or receive cash online or through your phone. The company now processes between $30 and $50 million per month in transactions. Read more

Back to the Roots

Nikhil Arora and Alex Velez got the initial idea for their business–to grow gourmet mushrooms in recycled coffee grounds–from a professor at UC Berkeley. Their business has now expanded to include do-it-yourself, grow-your-own mushroom kits, which are sold in Whole Foods, Home Depot and hundreds of other retailers. Read more

School House

Rachel Weeks started her line of fashion forward college-branded apparel with a manufacturer in Sri Lanka. But she soon discovered that bringing production back to the U.S. would not only be more practical, but also more meaningful to her young customers. Read more

Big Easy Blends

Craig Cordes and Antonio LaMartina started their portable frozen cocktail business in post-Katrina New Orleans. Think Capri Sun for drinking-age adults. With help from local incubator Idea Village, they now have national distribution and are on track for $27 million in revenue this year. Read more

Rebellion Photonics

Allison Lami Sawyer founded Rebellion Photonics with scientist Robert Kester at Rice University. They brought to market a fluorescent imaging camera that lets medical researchers take pictures through a microscope at 30 frames per second and enables energy companies to detect gas leaks within 15 microseconds. Read more

Mixbook

Andrew Laffoon and Aryk Grosz found photo-book websites boring. So they founded Mixbook, which allows multiple users to work on the same project and to pull pictures from Facebook, Flickr, Pinterest, and WordPress. They can then either share the project online or purchase it as a high-quality book. Read more

Zivelo

Ziver Birg founded his first kiosk company when he was just 18. Now, his company, Zivelo, is the second largest kiosk maker in the world. Among other projects, he has made digital menus for the White House cafeteria and virtual concierge booths for Hilton. Read more

Simple Energy

Yoav Luri and Justin Segall created a Web platform that, in partnership with big utilities like San Diego Gas & Electric, uses game mechanics to motivate consumers to save energy. People play online with their friends, earning prizes for themselves and at the same time cutting their utility bills. Read more

Massive Health

Aza Raskin’s mobile app, The Eatery, lets users snap pictures of their food, which the community then rates on an 11-point “fit to fat” scale. Users can follow and invite their Facebook friends to participate. Raskin has pilot programs with five employers who want to use the platform to reduce health care costs in their workforce. Read more

General Assembly

Adam Pritzker, Matthew Brimer, and Brad Hargreaves started General Assembly to offer classes focused on technology, design, and business–skills that help students get jobs. Their New York City campus is filled with not only students wanting to learn, but also with entrepreneurs and experts willing to teach. Read more

Spotify

Daniel Ek’s music streaming service, Spotify, has over 20 million active users who listen free with ads, or pay $5-$10 a month for premium service. In July, after years of negotiations with music labels, the 29 year-old Swede brought Spotify to the U.S. Three million Americans have signed up since. Read more

BaubleBar

In the spring of 2010, Amy Jain and Danielle Yacobovsky ditched their high-paying finance jobs and founded BaubleBar, an online retailer that sells private-label designer jewelry for as much as 60 percent less than brick-and-mortar stores. The New York City-based company, which just raised $4.5 million in Series B funding, projects $11 million in revenue in 2012. Read more

Synthetic

Lucas Buick and Ryan Dorshorst founded design studio Synthetic in 2008. The company’s signature product is photo app Hipstamatic, which boasts over 4 million users and brought in $10 million in revenue last year. Earlier this year, Buick inked a deal with photo-sharing app Instagram to let Instagram users apply Hipstamatic filters to their photos. Read more

Pinterest

Ben Silbermann was working as a consultant in Washington, D.C., when he grew fascinated by tech blogs. He moved to Silicon Valley, joined two friends, and created Pinterest, a social bulletin-board site filled with images that users want to share. Today, it’s one of the world’s biggest social networks, with nearly 20 million unique visitors a month and $138 million in funding.Read more

Codeacademy

While in YCombinator last summer, Zach Sims wanted to improve his programming skills. Ryan Buminski wanted to teach. In three weeks they launched Codeacademy, a site that teaches programming languages. By the end of 2011, the site had more than a million users. One of them could soon be New York City mayor Michael Bloomberg, who recently announced he wanted to learn to code. Read more

Geoloqi

Amber Case and Aaron Parecki developed a key technology behind a platform that manages location-based services for enterprises, app developers, and government services. Among other uses, applications built with Geoloqi’s toolkit are helping U.S. government agencies track people who’ve been sent into dangerous locations. Read more

Uassist.ME

Knowing that he and other entrepreneurs like him could benefit from having an assistant keep their lives organized, Alfredo Atanacio and Rodolfo Schildknecht founded Uassist.me, which offers English and Spanish speaking virtual assistants capable of helping with everything from travel arrangements to Quickbooks accounting. Read more

The Unreasonable Institute

Tyler Hartung, Daniel Epstein, and Teju Ravilochan founded The Unreasonable Institute, this year’s not-for-profit honoree, to incubate scalable social enterprises aiming to solve big world problems. Candidates raise their own tuition via online crowdfunding. Read more