Facebook has closed its purchase of Instagram, the popular photo-sharing app that it agreed to buy in May. The deal was valued at $1 billion when the companies agreed to it in April. However, Facebook's stock price has lost half of its value since then, so the deal is worth about $737 million, $300 million of it in cash and the rest in stock.

"As we said from the beginning, we are committed to building and growing Instagram independently. Instagram will continue to serve its community, and we will help Instagram continue to grow by using Facebook's strong engineering team and infrastructure. We also can't wait to work with the talented Instagram team to improve the mobile experience," Facebook said in a statement.

Instagram has a fast-growing user base of iPhone and Android users who take photos and apply various filters to them to share.