Linking your personal Google+ profile to your blog will automatically change the old Blogger Profile widget on your blog to the new About Me widget with a follow button. If your blog has more than one author, the widget will appear as the "Blogger contributors widget" instead of the "About Me" widget. The widget appears by default on Blogger mobile templates.
Having the widget on your blog makes it easier for others to access your profile and follow you on Google+ by clicking on the profile widget and the "View my complete profile" link. This may increase your blog’s discoverability and make it easier to form communities with other bloggers and readers.
How To Add About Me Widget With Follow Button
To display your profile gadget on your blog with a Google+ follow button:
==> Log in to Blogger dashboard
==> Go to the "Settings" > "Posts, Comments and Sharing" .
==> Scroll down to the Google+ section to link your blog to your G+ profile
==> Once linked successfully, go to Layout and click "Add a Gadget"
==> Scroll down and select "Profile"
==> Enter your desired title eg "Author" and SAVE.
If you tick the "show about me", option, a little description about yourself, pulled from your Google+ profile will be shown in the gadget as seen below. If the "introduction" part of your Google+ "About" page is blank, no description will be displayed.
If you leave the "show about me" unticked, the description will not be displayed as seen below.
If you have a team blog (with more than one author), your Blogger Profile gadget will automatically turn into a contributors-list gadget. In this case, you will have to remove the widget and replace it with HTML gadget containing the code of your personal Google+ badge similar to the one below:
The Google+ profile badge will not appear automatically on the mobile view of your blog like the default Blogger Profile widget. You must enable it in your Blogger mobile template if you want it to display on the mobile view.
Nevertheless, you can display the bio of your blog contributors directly under your blog posts if you enable the "Show Author profile below Posts" via the "Blog Posts" options. Read the full tutorial here.
Hope it works for you.
Do not forget to follow me ( +Jide Ogunsanya ) on Google+.