Apple has since released the redesigned Apple TV Remote app for iPhones. This will allow users to control their Apple TV using their iPhone, which also means that in the event you lose the physical remote, you’ll always have the app to fall back on. The only downside is that if your phone is out of battery, you won’t be able to use it (obviously).
The layout of the app is also designed to mimic the physical controller, so it’s not as if you’ll have to learn how to use it all over again. As pointed out by MacRumors, using the app is actually more efficient in certain ways, such as entering your username and password as you can type it out on the iPhone’s keyboard which is faster.
It can also double up as a gaming controller as it essentially packs the same sensors under the hood as the physical remote. If you’d like to get your hands on the app, just hit up the iTunes App Store for the details.