Mobile app development

I need full development. I am taking proposals. We launched a website called FPG family. It is a Christian media website. 24/7 Video and Radio channel, Multi show podcasts, daily blog, and video on demand. We are still building. I would like to know how you can help me develop the app. What would be the cost? Can you do it in our budget? I need IOS, Android, Roku, Apple TV. I would like it to be responsive so I can make additions and changes and it will respond across all platforms. Similar to Netflix. fpgfamily.com