Please put the pitchforks down and give me a second to explain. You cannot actually access Google+ as an Apps user, but you can access it without having to manually switch profiles or open up an incognito session of X or Y browser. Here is how:
…that’s it, really. At least for me. The important part is the
.../u/1/. It designates which user out of the stack you are logging in as. For me my default user (
0) is my Apps account, firstname.lastname@example.org and the actual Google account I use for G+ (1) is email@example.com. By using the link above I am telling Google to directly log me into G+ as firstname.lastname@example.org.
Simple and work-y.