The Rainbow Friends Call You - Blue Monster App is a prank application that lets you make prank videos and voice calls with your favorite Rainbow Friends character. It's 100% fake and fictional and designed to be enjoyed by everyone. It's very easy to use, and you don't have to download any other applications. You just have to download this one, and you can start using it right away. You can also enjoy this app differently. You can use it to prank your friends and family, and you can also use it to show off with your friends by taking screenshots during a video call and then sharing them on your social media.