Facebook has launched a photo-messaging app one week after accidentally releasing it on Apples app store.Known as Slingshot, the apps features include sharing photos and videos with friends and sending “reaction shots”.Like Snapchat, all images are deleted once sent and users can scribble or type over their photos.The app comes with an unlocking mechanism, whereby photos received from friends must be unlocked by “slinging” a photo back to the original sender.On the social media page for the app, the creators said: “With Slingshot, we wanted to build something where everybody is a creator and nobody is just a spectator. “When everyone participates, theres less pressure, more creativity and even the little things in life can turn into awesome shared experiences.”The app is developed by Facebooks Creative Labs division, which has been tasked with creating new and innovative products. Slingshot users do not need to have a Facebook account to sign up for the photo-messaging app. They can access the app with their mobile phone number and connect with friends in their phones contact list, or they can connect via their Facebook friends list. Snapchat competitor?