Facebook app head Fidji Simo joins Instacart as CEO San Francisco, July 9 (IANS) Fidji Simo, Vice President and Head of the Facebook app which reaches billions of people every month, has quit the social network and is joining online grocery leader Instacart as its CEO effective August 2, ahead of its IPO. Over the last decade at Facebook, Simo oversaw the development and strategy for the Facebook app, including News Feed, Stories, Groups, Video, Marketplace, Gaming, News, Dating, Ads and more. Apoorva Mehta, Instacart''s Founder and current CEO, will transition to Executive Chairman of the Board, and will also report to Instacart''s Board of Directors, the company said in a statement on Thursday. Mehta founded Instacart 10 years ago with an ambitious vision to bring an entire industry online and over the years he''s built and scaled a phenomenal business that supports the entire grocery ecosystem. "I''m excited to work with the talented teams at Instacart, as well as our retail partners, to reimagine the future of grocery, and create a world where everyone has access to the food they love and more time to enjoy it together," said Simo.