There are seemingly no problems that tech entrepreneurs won't try to solve. From health care to entertainment to education, founders often decide that there's got to be an app (or site or cloud-based platform) to shake things up. In the case of the companies listed here, the founders were right. Each one is changing the market it has entered, often extremely quickly. Here are 10 tech companies shaking up their industries:

1. Slack

A year and a half ago, Slack hadn't launched. Today, it has hundreds of thousands of daily active users and a valuation of more than $1 billion. What is it? A simple, some might say elegant, product. Slack was designed to help co-workers consolidate their communications in one platform. It's a messaging app, video and photo sharing service, and email replacement that integrates with Dropbox and other commonly used business applications. Adoption has been driven primarily by word of mouth. The company is making money by selling upgrades from the free, basic version to a subscription-based, premium service.

2. Everyday Health

A powerhouse in the online health information space, Everyday Health went public last year, raising $100 million on the New York Stock Exchange. The company used the capital to expand its portfolio, which now includes well-known names such as the Mayo Clinic Diet, Dr. Sanjay Gupta, and Jillian Michaels. The company also produces apps, serves advertising to health-oriented sites, and manages a premium subscription service for health practitioners. Everyday Health's market capitalization is only one-third that of the biggest competitor in its space, WebMD, but its portfolio is much broader and its product offerings more diverse, which boosts its growth prospects.

3. Andela

Andela, a "global talent accelerator," is aiming to alleviate the shortage of software developers by finding and training Africa's brightest youth to be programmers, and then placing them in jobs at American and European companies. Andela brags that it is harder to gain acceptance to its programs than to Harvard. Those who make the cut go through intensive training, and nearly all of the graduates wind up with virtual, full-time jobs. At the same time, employers get significantly more affordable tech talent.

4. Etermax

If there's anything as elusive in the tech world as the billion-dollar exit, it's the blockbuster app. Etermax achieved the latter this year with its release of the massive global hit Trivia Crack. Holding the No. 1 spot on the Apple and Android charts for over two months in the U.S. and many other countries, Trivia Crack has become the most downloaded app worldwide, with 130 million users. The company claims it spends little to no funds on advertising, but rather has experienced virality from word-of-mouth organic growth--an incredible feat if true.

5. Superfish

The idea of pure image-to-image search is simple. But the execution is very hard, which is why Superfish has a team of scientists working on it. Superfish's goal is to enable smartphones to process visual data--such as photos of a couch you like--and search for similar images. The trick is developing complex algorithms to parse visual data like humans can. By last year, Superfish had developed these kinds of algorithms, and the result is three apps that are currently available: one for furniture, another for pets, and the newest one for flowers. As users click through in-app links and then buy couches or other items that appear in the search results, Superfish takes a cut of the sale. The result has been dramatic growth, from sales of $135,000 in 2010 to $35.3 million in 2013.

6. Qubed Education

The next frontier in both publishing and university education might involve bringing the two together. That's the bet that Qubed Education is making, and it appears it might pan out. Qubed's vision is that traditional publishers, like Cond Nast, its first partner, have the ability to enhance university education with their real-world experience. The first test of this vision is a master's degree program that the University of Southern California will launch in partnership with Wired magazine in the fall. The degree program in "integrated design, business, and technology" will draw on USC's academic resources, as well as the working knowledge of Wired's designers, editors, and business writers. More degree programs, with other partners and universities, are in the works.

7. Kaltura

With its advanced open-source platform and OTT offerings, Kaltura has brought innovation to online video. From storage to distribution to streaming to analytics, Kaltura makes video easy for content owners. The company has raised over $100 million in venture funding, and with a wide swath of media, enterprise, and education customers--including TMZ, Harvard, and Bank of America--its technology reaches hundreds of millions of end users. Since last year, Kaltura has made a big shift into over-the-top content (OTT), deploying TV Everywhere solutions for Turner, Kabel Deutschland, and others. This video technology powerhouse shows no signs of slowdown.

8. Simpler Trading

Young professionals who are beginning to invest today are highly resistant to paying 1 to 2 percent of their assets to financial advisers to do something many feel they could do on their own. Simpler Trading aims to give customers the tools they need to do this. Subscribers get access to highly detailed guides in three investing categories: options, real estate, and stocks. Founded in Austin in 2010, the company has seen rocketing growth, with 2013 revenue topping $11 million.

9. RR Media

With content being king and competition in the broadcast world stiffening up, RR Media enables media companies to outsource everything except the creation of great programming. The company, which is listed on the Nasdaq, offers an ecosystem of media services that can manage, provide, and distribute content to 95 percent of the world's population. In an age when video consumption is increasing and demand for multi-screen experiences continues to explode, RR Media seems to be in the right industry.

10. Likeable Local

I'm obviously quite biased, but I'm proud of our software company, Likeable Local. At Likeable, we're building the world's first comprehensive social automation software for small and medium-size businesses (SMBs). The software includes content creation for and automation on Facebook, Twitter, and LinkedIn, listening and monitoring tools, mobile and SEO-friendly landing pages, an easy to use mobile app, and Turbopost advertising technology. We're about to launch a freemium VIP app as well. The $35 billion SMB advertising market is ripe for disruption!

Those are 10 of the growing tech companies on my radar. Now it's your turn. What tech companies have you been impressed with? Which have I missed? Please let me know your thoughts in the comments section below.