You won’t make a ton of money fast, but that doesn’t make Digit any less of an awesome app. Digit’s purpose is simple: the app analyzes your spending and automatically saves the perfect amount every day, so you don’t have to think about it. From the site, “Share what you’re saving for and Digit does the rest. It can budget for your next vacation, pay off credit cards, or put money away for a rainy day.”
Regardless if you need to earn some fast cash or we're just talking about making money in the grand scheme of things, there's an important psychology that needs to be mentioned before getting into the strategies. If you study Freud's model of the mind, you'll discover the Psychic Apparatus. It's the three-part construct in your mind that controls all of your behavior.