Image Credit: Garrett HeathTwitter, the microblogging giant whose headquarters sit on a section of San Francisco’s Market Street that’s not exactly fancy, is set to open a learning center for the homeless next summer. The learning center, which the company announced in partnership with Compass Family Services last May, will be located across the street from Twitter, at Essex Fox Plaza, 1390 Market Street, and will open next summer, according to a San Francisco Chronicle report.