Gemiini Mobile App does not support casting,  but many devices can connect to an external display through an HDMI cable. There is also a Gemiini Roku Channel available now on Roku devices. Also, If you have a laptop available, you can connect the laptop directly to the TV and play videos via the website on the TV. You can do that by plugging the laptop directly into the TV with an HDMI cable and then playing the videos via the website just mirrored onto the TV.