I am able to both build and load the Windows 10 IoT Core ffu onto my i.mx6 sabre board but I'm unable to load any applications.
Start->WIndows Device Portal -> Packages only show my installed packages (IoTUAPOOBE and IOTCoreDefaultApplication) but I don't have the ability to load my UWP application (.appxbundle)
What is the best way to load you apps into Windows 10 IoT Core Demo image of the i.mx6 Sabre Board
Please follow the general Windows 10 IoT Core documentation for adding application to your Windows 10 IoT Core image:
Try to add the application to the image as described here:
Microsoft claims the method above as the preferred one.