In addition to the simulator / SDK, I'd recommend also building your apps with iPhone/iPad support because the codebase will be 99% the same and you can get try out how it works in "real" AR instead of a simulated environment.
Not saying you need to actually release iOS apps, just that it will help development over the next year.
👤 wilsonnb3
The initial, ready-on-release apps are largely going to be from companies or developers with enough clout to have early hardware access, probably in a secret room hidden in the depths of Apple HQ.