Crowd testing involves using an online community of testers from diverse backgrounds to test software. UTest is a crowd testing platform with over 60,000 professional testers from 190 countries. It allows customers to define test scopes and select testers to test web, mobile, and desktop applications on real devices under real-world conditions. Testers on UTest are paid per accepted bug or test case executed, with payment twice a month. While crowd testing can help learn and earn money, there are disadvantages like not getting paid for duplicates or rejected bugs.