Our current Android / iOS application uses Google's Cast SDK to provide casting to Chromecast enabled devices, but I can't for the life of me find an equivalent library for Roku.

What is the best way to integrate casting to multiple devices devices (Chromecast, Roku, FireTV) from our app and can anyone please point me to Roku's equivalent documentation to Google's Cast SDK?

Thank you.

Signed,
I just spent two hours Googling without finding any help.