I've experienced some difficulties when using Oracle Application Express (APEX), particularly when I'm designing forms. For example, when I design a form, I add buttons and controls, but I'm unable to visualize how it'll look unless I run it. You want to design and do things your way, but if you don't have much experience, then you'll find that designing in Oracle Application Express (APEX) is a little complicated. This won't be a problem with anyone more experienced, though.
If I wanted to create my design, for example, a different table format or some background images, it becomes a problem, and this is an area for improvement in Oracle Application Express (APEX). Designing should be easier, even for less experienced users.
An additional feature I'd like to see in Oracle Application Express (APEX) is more plugins, particularly a repository that contains a lot of plugins, so you can go to that repository and download whichever you like and use it or add it to your project. Right now, I create my plugins, so it would be helpful if Oracle Application Express (APEX) has a repository of plugins people can use, download from anywhere in the world, and integrate into projects.