After accidentally releasing the Snapchat competitor Slingshot on iOS last week, Facebook launched its new photo messaging app on Android and iOS in the United States.

Can't say it's a first, but Facebook's new addition is slightly different from the other messaging applications. Slingshot by Facebook is ready to take on Snapchat, which declined the social network's $3 billion acquisition offer last year. The new photo messaging app's core function is similar to Snapchat's disappearing photo concept, but  Facebook claims that it comes along with new layers built atop to differentiate it in the crowded market.

 Facebook, the world's largest social networking service, accidentally leaked the first copy of Slingshot on Apple App Store, last week, and also confirmed it was an error. But the company seems prepared for the big day as it officially announced the launch of Slingshot and detailed some of its functions in a new blog.

How does it work?

 Slingshot is built upon the concept of ephemeral photos and videos like Snapchat, but with one major difference. A recipient won't be able to view the message unless he or she sends back a response photo or video. The idea behind this concept is to engage users on both ends.

Facebook might be playing the curiosity card here to tempt users to find what message one has received and 'forcing' one to send "reaction shots." This unlocks the photos and videos received, which will disappear after viewing and clearing them.  

"When everyone participates, there's less pressure, more creativity and even the little things in life can turn into awesome shared experiences. This is what Slingshot is all about," the new official Slingshot blog read.

Developed by Facebook's Creative Labs division, Slingshot is independent of whether a user holds an account with the social network. Users can connect their phone number and get started, or, if they want to, connect with friends via Facebook friends' list.

The photo messaging app also lets users add some text and color before "slinging" it to a friend or a bunch of friends at the same time.

The app is available for download only in the United States for now, with no specific time frame for a global release. Download Slingshot on Android and iOS for free from Google Play Store and Apple App Store.