To customize the settings for a particular application, you will first need to run that application. Make sure the application has focus, then press Orca_Modifier+Ctrl+Space (by default, this will be Insert+Ctrl+Space for the Desktop keyboard layout).
This brings up a tabbed dialog window very similar to the Orca configuration dialog, but with the following differences:
Adjust your application-specific settings in the same way you set your general Orca preferences. For example, you may have Key Echo disabled generally in Orca but would like to specifically have it enabled for the gcalctool (GNOME Calculator) application. Here's where you could easily set that.
When you have your application settings customized the way you want, press the OK button. These settings will be written to your ~/.orca/app-settings directory in a file called <APPNAME>.py, where <APPNAME> is the name of the application.
These files are automatically written by Orca. The contents of the file will be overwritten each time you change your application settings for that application.
If you want to have some extra application-specific settings or code that you don't want to lose, then you should put it in a file called ~/.orca/app-settings/<APPNAME>-customizations.py. This file will be automatically read when the settings for the <APPNAME> application are loaded.
Note that this is an advanced feature that we don't expect many people to use. It's just there if you really want it.
There is currently one known bug (some people would call it a feature) that we are trying to track down and fix:
If you adjust one or more application-specific key bindings, the new values will not take effect until you've pressed the OK button. The work-around is to either restart Orca, or Alt-Tab away to some other application and then Alt-Tab back to the one that you've just changed the key bindings for.