Using an app has inherent security implications (it's very, very hard to trust apps). However, I agree that in terms of security, using an app with local control is better than something cloud-connected.

My primary issue with requiring the use of an app is that apps are a pain in the ass. Allow the use of an app as an option, sure, but the appliances should be able to be fully used with the controls on the appliance itself as well. Requiring the use of an app is a dealbreaker for me, but for usability reasons more than security reasons.