Under Windows 10, Universal Apps (Windows Store apps) are handled differently by Windows than classic Desktop apps. In order to run a Universal App as a Desktop app, Windows wraps the app in a "frame." Thus, when using a Universal App as your Master Application, it requires a different setup than typical. Basically, configuring a Universal App to work as a Master Application is similar to the setup of a Master Application that requires a launching program (like a script, or batch file).
We'll use the Windows 10 Sports app as an example. Below is what's populated under the Secure Lockdown Master Application tab:
Application: C:\Windows\explorer.exe
Process Name: Microsoft.Msn.Sports.exe
Arguments: shell:AppsFolder\Microsoft.BingSports_8wekyb3d8bbwe!AppexSports
That's seems easy enough. The question is where do you find the app information to populate these fields.
1. The Application field is always "C:\Windows\explorer.exe".
2. To get the Process Name field info, Run the program in Desktop Mode, then open Windows Task Manager and find the process under the Details tab. Once found, right-click on the process and select the "Open file location" option.
3. To find the Arguments info, press the Windows key plus R (Win + R) to open the Run dialog. From here, type "shell:AppsFolder" and press OK. You will see all apps.
4. Find your app and select it. Then select the "Choose details..." option from the "View" menu option.
5. Check the "AppUserModeId" column option and select "OK." If you dont see the "AppUserModelId" column, change the Window view to Details. You will then see the AppUserModelId of your app. You need to type "shell:AppsFolder\" plus this information into the Arguments field (see example above) in Secure Lockdown (you can't cut-and-paste it).
Now press the Test button in Secure Lockdown to be sure your Windows 10 Universal App runs as expected.
If you need to run your app in Tablet Mode:
First, set Windows to always launch in Tablet Mode upon signing in (Settings > System > Table mode > When I sign in > Use tablet mode).
Second, disable Multitasking so that users can split the screen by dragging downward on the touchscreen (Settings > System > Multitasking > Snap > turn off "Arrange windows...").
Finally, launch Secure Lockdown before enabling Tablet Mode, then, enable Tablet Mode. From there, use the Alt+Tab key sequence to display Secure Lockdown and enable it.
Note that you cannot enable the System Lockdown > Local Level >No Desktop feature in Secure Lockdown as Universal Apps require the Windows Shell to be running (explorer.exe)
