To use AirPlay, to stream Bingo Machine to your big screen wirelessly, you need an Apple TV and an iOS device that supports AirPlay Mirroring; iPhone 4S and later, iPad 2 and later.
Then, enable AirPlay Mirroring on your device and open Bingo Machine. On the external display, the current ball is shown large, for maximum visibility.
Depending on the display's contrast, a black-on-white theme may be more preferable to the default white-on-black. This option can, therefore, be customised in app's settings.