Switching between my profile on Google+ and a page I manage I have a Google+ account. I manage a page there, too. But how to switch between them using an Android device that its version is 4.2.2?
In the Google+ app, tap the "hamburger" menu in the upper left. It should show your cover image, your profile image and name, and a menu of options: Home, People, Photos, etc.

Tap the downpointing arrow next to your name.

You will probably1 see an option to "Select Google+ page" with a right-pointing arrow. Tap that. 

Now you should see your page(s) available in a menu. Tap it.

You are now using Google+ "as" that page.

To go back to your personal profile, follow the same steps, but choose your profile where before you chose your page.



1If you've done this before, then the page you used before will be listed here along with "Switch Google+ page" (if you have more than one page to manage). This also assumes that your Google+ account is set as a manager/owner of the page in question.