He Tom,
I'm using PhpStorms and haven't found one yet.
There is a trick to give you some sort of autocomplete feel using the following header code in you're controllers / models.
Code:
/**
* @property CI_DB_active_record $db
* @property CI_DB_forge $dbforge
* @property CI_Benchmark $benchmark
* @property CI_Calendar $calendar
* @property CI_Cart $cart
* @property CI_Config $config
* @property CI_Controller $controller
* @property CI_Email $email
* @property CI_Encrypt $encrypt
* @property CI_Exceptions $exceptions
* @property CI_Form_validation $form_validation
* @property CI_Ftp $ftp
* @property CI_Hooks $hooks
* @property CI_Image_lib $image_lib
* @property CI_Input $input
* @property CI_Language $language
* @property CI_Loader $load
* @property CI_Log $log
* @property CI_Model $model
* @property CI_Output $output
* @property CI_Pagination $pagination
* @property CI_Parser $parser
* @property CI_Profiler $profiler
* @property CI_Router $router
* @property CI_Session $session
* @property CI_Sha1 $sha1
* @property CI_Table $table
* @property CI_Trackback $trackback
* @property CI_Typography $typography
* @property CI_Unit_test $unit_test
* @property CI_Upload $upload
* @property CI_URI $uri
* @property CI_User_agent $user_agent
* @property CI_Validation $validation
* @property CI_Xmlrpc $xmlrpc
* @property CI_Xmlrpcs $xmlrpcs
* @property CI_Zip $zip
*
* Add additional libraries you wish
* to use in your controllers here
*
* @property Accounts_model $Accounts_model
*
*/
Mind that this is voor CI 2.x.x. If you're using CI 3 you maybe have to change some class names.
Hope this helps.
Roger