We are looking to use a song in the background where people do a quick video of them lip syncing the audio of song. We would then put the video clips with the song in the background together so it is one video with the audio playing in background. Are their any iOS/Mac/Web applications that can simplify the process? We are thinking of either recording everyone doing the whole song and then putting together the clips; or having each person do a small part of song. It would be great if there is some sort of service out there that can make this process easier. I know I could use iMovie; but this is going to be very time consuming.