Say I have a company named Moose with an app called Moose.
Is it okay to create a package name like "com.moose.moose"?
Is it okay to create a package name like "com.moose.moose"?
If you own the moose.com domain, yes. You can use com.moose or com.moose.moose or com.moose.moose.moooooooooooooooooooooooose if you want, along with anything else that has com.moose in the first two segments.
If you do not own the moose.com domain, then I recommend that you use an application ID that is based off of a domain name that you own. Otherwise, the owners of moose.com could take issue with your application ID and cause trouble (mynd you, møøse bites Kan be pretty nasti).