San Francisco Flex Academy is a tuition-free public charter school for students in grades 9-12. This is one of California's first, full-time hybrid schools. It exclusively uses curriculum developed by the for-profit online curriculum organization, K12 Inc. Core subjects are English, math, science and history. Students can take electives that include art, technology, world languages, anthropology, and journalism.
Reviews from parents and students, as reported on GreatSchools.org, are mixed.
Here's a report from the Innosight Institute on the Flex Academy's blended learning program.