I just bought a Gamesir T1D. Here in the Philippines it is available at the DJI store. You can find online on Amazon. Please remember that the Gamesir T1D can only be used on the Tello, and cannot be used to play games on your iPhone. What this means is the pairing with the controller is done within the Tello App and not through iOS Bluetooth Settings.
Both Tello and Tello EDU are made by Shenzhen Ryze Technology and incorporate DJI flight control technology and Intel processors. These compact and flexible drones allow you to enjoy aerial photography and explore acrobatics in the air.