Riff lets you film videos and uploaded them to th e app . Friends and strangers can then film relevant clips and attach them to the end of your video . Despite being launched on April Fool 's day , and using an # AprilFools hashtag to promote its features , Facebook 's latest app is reportedly not a hoax . Called Riff , it lets you film videos and upload them to Facebook and the app . Friends and strangers can then film relevant clips and attach them to the end of your video to create a collaborative project . The app was created by London-based developers through Facebook 's Creative Labs . It is available for free on iOS and Android . The app 's homepage has a row of Featured clips , each tagged with a certain topic . For example , one tagged # balancingact features six clips in total and includes a dog balancing a banana on its head followed by a skateboarder , and a woman balancing books on her head . Each video has a counter that shows how many clips are attached , and which clip in the sequence the viewer is currently watching . It also shows how many people have viewed the total project . Individual clips can be reported for inappropriate content , for example , by clicking the menu button in the top right-hand corner of a clip and clicking the red whistle icon . Elsewhere , videos can be shared on social networks , over email and in messaging apps . It does n't reveal what the maximum number of clips in a project is , but each clip can be no longer than 10 seconds . The app 's homepage has a row of Featured clips , each tagged with a certain topic . For example , one tagged # balancingact features six clips in total and includes a dog balancing a banana on its head followed by a skateboarder , and a woman balancing books on her head ( pictured ) To start a video , users click 'Start new video ' , choose a topic ( left ) and press the arrow . Videos can be filmed multiple times until the user is happy with the result , and then the clip is uploaded . Each video has a counter that shows how many clips are attached and how many people have viewed the project ( top right ) To start a video , users click 'Start new video ' , choose a topic and press the arrow . Videos can be filmed multiple times until the user is happy with the result , and then they are uploaded . All videos are public . Each video has a counter that shows how many clips are attached , and which clip in this sequence the viewer is currently watching . It also shows how many people have viewed the total project . Individual clips can be reported for inappropriate content , for example , by clicking the menu button in the top right-hand corner of a clip and clicking the red whistle icon . And to start a video users click 'Start new video ' , choose a topic , and press the arrow . Videos can also be filmed multiple times until the user is happy with the result , and then they are uploaded . All videos are public . 'Having fun with friends is at the heart of the Facebook experience , ' said Facebook in a blog post . 'Our hunch was that if you could make videos collaboratively , the creative process would be more fun and the final product would be cooler . 'Today , we are introducing Riff , a creative tool to make videos with friends . ' Once a friend adds a clip to a video , a user 's friend ’ s friends will also be shown the video in Riff and will be able to add to it . 'The potential pool of creative collaborators can grow exponentially from there , so a short video can become an inventive project between circles of friends that you can share to Facebook , or anywhere on the internet , at any time , ' continued the blog post . If it is a hoax then it is an elaborate one that Facebook has continued for longer than April Fool 's Day .
Riff was developed in iOS and is available on Android and London . It lets you film a video and uploaded it to the app and Facebook . Friends then film their own clips and tag them onto the end of your video .