The Twizoo mobile app uses colours and font sizes as cues to recommend the best places to eat and drink based on real-time Twitter conversations.
"We're thrilled to have Twizoo now available in San Francisco," said Twizoo cofounder and CEO Madeline Parra, who has had to overcome sexist venture capitalists when raising money for her company.
"With such a vibrant restaurant and bar scene, combined with being the home to Twitter, San Francisco is the perfect city for Twizoo to help people find the best places to eat or drink based on what real people are tweeting."
Twizoo, which has now raised a total of £1.45 million, also introduced a new feature called Community to users in London and San Francisco.
Community provides users with a fresh stream of content about the restaurant and bar scene as curated by the Twizoo algorithms.
It includes weekly leaderboard lists that highlight the top Tweeters about food and drink, along with a real-time feed of their foodie tweets. Community also gives Twitter users instant access to their tweets that have made it into Twizoo, as well as tweets from their network.
John Talbott, Twizoo cofounder and CTO, added: "When chatting with our Twizoo users, the number one feature they wanted was an organised view of their own foodie Tweets, and also those from the wider Twitter-sphere.
"With Community, we are doing just this - regardless of whether you use Twitter or not. We're organising Tweets about restaurants and bars not only for recommendations, but to give users real-time collections of foodie Tweets from their network and from the cities' most prolific Tweeters about food and drink."
San Francisco is a natural expansion ground for UK startups offering city insights on everything from food to navigation, with urban navigation app Citymapper launching there last September.