Set a Custom Background Image on Google+ with Layouts for Google Plus
Layouts for Google Plus is a new Chrome extension that lets you personalize Google+ with a custom background image.
Once installed, the extension takes you to its website where you can select an image from the public gallery. If you want to set your own image as the background, that can be done as well by uploading an image from your computer. Right now it doesn’t offer an option to select an image that’s already hosted somewhere online.
Images that you upload can be kept private, by ticking the “automatically adding it to the public gallery. Images once uploaded cannot be deleted, so be careful what you upload.
The extension also adds a quick access “Change Background” button next to the existing “Send Feedback” button in the lower right-hand corner of the page. This button redirects you to the extension’s website. To see the new changes in effect, you may need to reopen Google+ in a new tab.
Set background image is visible on all Google+ pages but is visible only to you, and only if you’ve the extension installed in your browser. Still it’s a nice option to personalize Google+ or a change if you are bored with the plain default background.
Install: Layouts for Google Plus