If you want to prevent the user from deploying your Windows Phone 8.1 app in SD Card , you can do it by updating the WMAppManifest.xml file.
How to Prevent the deployment of Windows Phone 8.1 App in SD Card ?
Follow the below steps to do it.
1. Double Click and open the WMAppManifest.xml . This will open the WMAppManifest.xml in GUI designer.
2. Navigate to the Packaging tab .
3. Enable the checkbox “Prevent deployment to SD cards” and save the project.