San Francisco -- Ringadoc, a San Francisco-based virtual health startup, said on Thursday it has landed $750,000 in a round of seed funding, led by FF Angel, the seed investment vehicle of Founders Fund. Board member Ryan Howard, the founder and CEO of Practice Fusion, and technology incubator Curious Minds also contributed. Ringadoc facilitates on-demand virtual doctor visits over any phone, smartphone or computer. Licensed and verified physicians provide health advice, diagnoses and even prescriptions when warranted. The company will use the seed funding to build a new product offering for physicians to use directly in their offices, as well as for key hires.