Just upload these files into your CodeIgniter application folder and set the config variables. You can then load the library like this
$this->load->library('googleplus');
Example usage:
$this->googleplus->people->get('me'); // when authorized
$this->googleplus->people->get('115414977082318263605'); // that's me :-)
Read the full API docs on the Google+ website http://developers.google.com/+/api
Uses the Google APIs Client Library for PHP
http://code.google.com/p/google-api-php-client/ samwierema/google-plus-api-codeigniter
Wrapper for CodeIgniter around the official Google+ API PHP library
PHP