Sure, there are some options like blogging that can make you a full time living but it takes a lot of hard work and dedication. But the majority of these methods, like surveys, reviewing, money making apps and so on, are not going to help you quite your day job. They are great for earning a little side cash in your free time. There is no need for me to hype things up and tell you otherwise.
One of the most underrated freelancing sites ever. The site started as a place where you could get paid to do short tasks for just five bucks. Over the years, it has slowly morphed into one of the biggest gig/freelancing sites where you can now charge any amount to do all kinds of stuff for other peoples. Anything from serious stuff like copywriting, translation, voice over social media management to silly stuff like prank calls and everything in between.
Providing a service may be the easiest way to start because you don’t need any investment to get this going. My podcast editor Ian Robinson is helping podcast creators edit their shows to increase production value. There are many different ways to provide a service and it’s just about realizing where your talent lies and what solution you can provide for others.
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.
Be professional. When you submit a résumé, don’t type it in ALL CAPS and please don’t avoid the caps lock like the plague. Know how to use it without looking incompetent. Write in complete sentences with proper grammar. Of course, there will be exceptions, but even with the exceptions, you must keep it professional. You’re building their view of you.