No. You can only replace the one headed startup application there is with your own.
Best not to do it with a development app, only a Release v.1.0. though
You can start other things from the web interface though so all hope is not lost but that wont help you probably.
From the Web management portal
Apps
Provides install/uninstall functionality for AppX packages and bundles on your device.
Note that Windows 10 IoT Core only allows you to have one app running in the foreground at a time.
ricl : F/gamma = ma : Law ii(a) : https://climatedatablog.wordpress.com/2016/01/02/an-energy-challenge-2016/ #AnEnergyChallenge2016