Wait, so you put out this launch announcement telling people they can early register .app domains. It links to a bunch of partners including Google Domains, but you have no idea whether I can actually register a domain there or not? Why promise it in your launch announcement then?
Choice of domain registrar is up to the end user. We cannot recommend any one over the other. There are plenty that are offering the full range of registrations/preorders (including EAP), and you need to pick your own.
It costs end users ~$20, for whatever's left over after the seven rounds of expensive "priority access" pick over the namespace carcass... At least for the two out of three resellers I tried (Google themselves still don't appear to know this exists...)
