Upshift is an app that allows you to pick up shift work from local companies. The app is easy to use, and there are legitimate jobs available.
Gigwalk is a mystery shopping app. It allows companies to list tasks that verify that their brand image is being properly conveyed in the real world.
Task Rabbit is a gig-based app offering money to perform tasks for others.
KashKick is an app that pays you to take surveys, play games, watch videos, and complete tasks.
Amazon Mechanical Turk allows you to complete microtasks and get paid for them. The tasks usually verify things that are hard for amazon to verify pragmatically.