However, like anything else truly worthwhile, apps require a significant investment of your time or money upfront. If you don't have the skills, then you have to hire someone who can assist you in creating a great app. But first you need to come up with an idea that will sell. Do the proper market research and analytics to come up with the right app.

If you’ve got a way with words and expertise in a niche, there are plenty of sites that will pay for articles and content you write. Think of the sites you read regularly. What can you contribute to them that would be interesting? Research your niche and then look for ways to pitch articles. Many sites will simply have a submission or contact link in the footer. To get started, check out my full guide to becoming a freelance writer on the side and then submit your articles to places like Listverse, A List Apart, International Living, FundsforWriters, and Textbroker.


Love dogs, but not ready to get one of your own? Get your fix by taking care of other people’s pooches — and get paid for it. If your home isn’t dog-friendly, consider becoming a dog walker. Apps like Wag! offer on-demand dog walking, so you can pick up walks when your schedule allows. If you have space (and your landlord’s permission, if you rent), offer overnight dog boarding. Dog sitters on Rover.com, the go-to site for pet-sitting, generally command $25 to $35 a night, according to the company.
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