The startup announced the deal on its website this morning (June 18).
"We love building products, and like our friends at Facebook, we think that mobile is a critical part of people's lives as they both create and consume content, and share content with their social graph," the announcement read.
"By working with Facebook directly, and joining their team, we'll have more opportunities to build amazing products that will be employed by consumers - that's all we've ever wanted to do."
The terms of the deal have not been disclosed, although the new announcement suggests that Facebook may be making moves to add new photo-sharing features for users.
The social networking site, which recently settled a lawsuit over its 'sponsored stories' policy with a $10 million charity donation, also bought the popular photo-sharing application Instagram in April for $1 billion.