That makes Google’s Android XR – on the first headset to use it at least – the most open of the three major standalone XR platforms by far. Apple’s visionOS doesn’t allow sideloading at all, except for developers compiling their own app from Xcode on their Mac for testing purposes. Meanwhile, sideloading on Meta’s Horizon OS requires registering as a developer, which involves providing Meta either your phone number or payment card details for verification. And even then, you need to connect an external device like a PC to your Quest to start sideloading.