Castamash - duet videos app for iPhone and iPad

Castamash is the first social app that allows people to create collaborative videos with friends, no matter barrier in space and time. Start your mashup by recording the left part of a split-screen video and send it to a friend. Keep in mind that your friend will then record the right side of the video while watching your part. Final result: you and your friend interacting together in a single video!
Send your friend a kiss, you will be kissed back! Send a fist bump and get it back! Ask a question and get an answer...Or launch a football and see if your friend catches it :)
Enjoy the app in any possible way you want and let us know what you think about it!