Both Sittercity and UrbanSitter let you either browse profiles of babysitters and nannies for hire, or post a job listing and let caregivers respond to it (which is great if you’re in a last-minute bind). The services do background checks, and you can read reviews from other parents before you book. The apps themselves are free, but both sites require a monthly membership fee ($12/month if you pay upfront at Sittercity, $10.50 at UrbanSitter) before you can start using their services. Cost: Free
