What’s it about ? Ta-Dah is a new app where you can invite friends, create groups, and challenge them to do anything you dream up. The friends you invite are the only ones who see the challenge, and you and the friends you invite are the only ones who can see how everyone you invited responds. You decide when it starts, and how long it lasts, anywhere from an hour to 48 hours. At the end of the challenge all videos are purged / removed / gone.
Another option is to allow the friends you invite, to invite other friends … that’s your choice.
Just remember when dreaming up your challenge, that your friends can also challenge you.