Mobile FAQ | Roku Streaming Player
https://wwwimg.roku.com/mobile/faq.htmlIf you have multiple wireless routers in your home, check that your Roku device and phone are connected to the same router (same SSID). If the app still does not show your Roku device, try powering down your Roku device, phone, and router. Restart all devices, wait 3 minutes, then launch the Roku app again.