You can look at:
1. Image files
A new feature of APEX 3.0 allows browsing of images that are part of the APEX distribution and available for use, located in following directory:
From the 'Application Builder', from the shortcut menu click on the 'Find' torch, pictured below.
This will load a popup, where you can search a whole load of useful APEX stuff, of interest here is the 'Images' tab. Click this, ensure 'Show' is set to 'Standard Images' and you will be able browse the images currently available. By clicking on an image, APEX will also provide you with a link to be used in your application.
Note: This technique can also be used to view cascading style sheets available to you. These CSS shown here are solely the theme independent ones and thus always available to you regardless of theme.
If however, you wish to view a specific CSS file via the browser, read on...
You can look at other files that are contained within the images directory on the server (not just images!), via the virtual path specified in the following configuration file:
This can be done directly from the browser by removing everything after the port number and replacing it with a path to the file you wish to look at. This would typically be used to look up a '.css' or '.js' file that the current page references, something like:
3. Activity Logs
Although you cannot see the exact access_log files from the browser, there is a report which shows similar information, which can be accessed via:
Home > Utilities > Application Express Views > APEX_WORKSPACE_ACTIVITY_LOG
This contains information like workspace, application, apex_user, page_id, view_date, think_time and ip_address to name a few.