Is there a plugin that allows me to change the url of domain.com/wp-admin to domain.com/whatever-iwant ? Curious if there is an easy solution to this by now.
If you're looking for a way to physically move the wp-admin folder to another location, that is indeed problematic. That's why there is not an easy solution available. Not that it isn't just easy, it is even the opposite. The directory name "wp-admin" is hardcoded deeply into wordpress. This is by design, so wordpress actively prevents to allow a change here.
Naturally you can solve this by hacking core and/or by reconfiguring the directory layout within your file-system and the server configuration in addition with a plugin.
This is another related question: Can I rename the wp-admin folder? with a detailed answer by mike.