Developing a project on CodeIgniter, with so many libraries and helpers that the framework offers and with so many other classes of its own and / or third parties without the autocomplete feature that current editors and IDEs offer is insanity. It is very difficult to know / remember all the methods of a given class, what they receive as a parameter and what they return.
I develop my projects on NetBeans , and although it provides a huge range of code autocomplete suggestions for PHP’s native functions and even some frameworks, for CI we have to configure this feature manually.