That is a great question! You can add 29 applications to the Application row in the Setting program. Technically there are 30, but one is the default "All other," so that leaves 29 applications for you to add and customize.
The advantage of adding an application to the Application row is that you can customize your Pen, Tablet, and Quick Keys for that specific application, The custom setting will only be applied when that application has focus (being used).
By default, you will have "All Other" in the Application row.
If you customize your tablet now, it will affect all the applications you will use. This is good, but not great.
Adding the application you want to customize to the Application row will allow you to make custom changes to that specific application. That ability to edit each of the applications you add to the Application row transforms this tool into a great feature.
I'll place a link at the bottom that will work you through adding your application to the Application Row.
For example, if you are switching between PS  and Lightroom , you can change your Pen, Tablet, and Quick Keys settings.
The image to the right shows the Yellow bar is under PS . This indicated that PS has focus, and any changes you make will only affect PS.
Once you have finished setting up your custom settings for PS, you can click on the Lightroom icon , and the Yellow focus bar will then be active for Lightroom. Any changes that are made now will affect only Lightroom.
 This shows that the Red color will be used for the active area lights when PS  is being used. You can use each of your programs set up for a different colored light.
To expand on this; You can also set up the Pen to have different settings depending on the application being used.
In the image to the right, PS  has focus, and the 3-Button pen  is selected, the Pen Pressure has been adjusted.  This adjustment to the pen pressure will only be used with PS and only when the 3-Button pen is being used.
You can set up a different pen pressure setting for the Thin Pen to be used with PS.
This will allow you to have two pens that you can use with PS that will have different pen pressure characteristics when used.
This is the start of how you can create custom settings that will be used with a specific tool, and application, thus increasing your workflow and effecentcy.
This link will take you to the instruction that will walk you through adding an application to the Application row in the Setting Program: https://solutions.xencelabs.com/en/support/solutions/articles/67000544218-how-can-i-make-custom-settings-to-a-specific-application-
If you would like to reach out to Customer Care, please go to support.xencelabs.com.