If you bought a game controller for the new Apple TV, odds are it was the SteelSeries Nimbus. The $50, £40, AU$95 controller is available in Apple retail stores, is predominately displayed on Apple's site and even bundled with Disney's Infinity 3.0 pack for Apple TV.
Even if you've already paired it to your Apple TV, or if you're unboxing it for the first time, take a moment and update the controller's software in order to get the most out of the handy accessory.
In order to update the firmware, you'll first need an iOS device with the SteelSeries Nimbus Companion App installed.
Once the app is installed, pair the controller to the iOS device by powering up the controller, then holding in the Bluetooth button until all four lights blink simultaneously on the controller. Launch the Settings app on your iOS device, then go to Bluetooth and tap on Nimbus from the list of available devices. Last, launch the Nimbus app.
When a software update is available, the app will prompt you to install it right away. The process takes just a few seconds. Just be sure to leave the controller powered on and connected to your iOS device until the app lets you know the upgrade has finished.
You may need to re-pair your controller with the Apple TV after the update is finished.
I've yet to find a change log posted anywhere online or within the SteelSeries companion app, however. That said, it can't hurt to have your controller(s) updated with the latest and greatest software.
The Nimbus app also provides you with a list of iOS apps that support the controller, meaning you can use it to play games on your iOS device instead of tapping away on the touchscreen.