IOS App development for a magic show

I have a project that I was wanting created for an iOs device. Essentially I am a performer. I will ask the audience go onto a website. I can then send information to their phone using (using pub nub) such as change to green and there screen will change to green, change to blue etc and then open my instagram page on their phone remotely. This has done before so can give you instructions on how to achieve but knowledge of Pub Nub is important. I can send you a video of how this can work too....