A few years ago, starting your own business required a herculean amount of effort. You had to find office space in town, meet with loan officers to get funding and spend a full day in the courthouse to get a license to operate – and that was just the tip of the iceberg. Opening a business was a costly and –for many would-be entrepreneurs –prohibitively risky endeavor. But then smart phones hit the market, and things changed.

The rise of mobile OS begat the rise of e-commerce, and now starting your own company is easier than ever. You just need a good business model and a smart phone with a data plan. For example, here are four businesses that require nothing more than an email address and a few useful apps to get started.

1.      Professional Power Seller. Amazon may dominate the online marketplace these days, but there are still millions of people who prefer to do their shopping on auction sites like eBay. If you’ve got an eye for merchandise, you can turn selling goods on Internet’s largest bidding house into a career. Just download eBay’s mobile app and start scouring your local thrift shops and flea markets.  Buy things cheap and then sell them for a markup online. Its hard work, but being a power seller can definitely earn you a living. Check out eBay’s Professional Sellers Alliance for more tips on how to get started.

2.      Contractor. Have a knack for home improvement? Why not turn it into a living. If you’ve got your own tools, all you need to do is obtain a license and you can work as a professional contractor repairing leaks and creaks for hapless homeowners. With the ability to manage your appointments through GenBook, organize your personal finances through Mint and market your new business through apps like Craigslist, the overhead for this profession is incredibly low. Just slap your company logo on your pickup truck or minivan and you’ll be good to go.

3.      Tech Support.  Lots of people need help with their computers, and if you have professional experience in IT then opening your own tech support company might be your calling. This is a business you can easily run from home through your phone using apps like LogMeIn to give you remote access to computers and YuuGuu to run online conferences and collaborative sessions.

4.      Social Media Manager. Using your own social network as a resume, sub-contract out your networking skills to companies who want to enhance their presence online. You can manage all of a company’s networks through apps like HootSuite and TweetDeck while using SpredFast to measure analytics and generate reports for your clients.

The myriad of free and low-cost apps available to entrepreneurs have made starting a business more feasible than ever before. Sure, founding a company through your smart phone might not be the simplest of tasks, but many professionals will testify that it can certainly be done. So the next time you have a weekend free, try it for yourself. If you’ve got a good plan and a solid work ethic, you might be surprised at just how successful your “pocket company” can be.