There are some iphone apps that can control all devices in HomeKit. Look for an app called simply "Home". It should show all of the devices you have added to HomeKIt from their respective vendor-specific app. This in theory will allow you to add only the "Home" app to family member's phones, and only install the vendor-specific apps on your phone (in order to add new devices).
Here's a review of the "Home" app:
http://www.imore.com/home-app-progra...hipped-homekit
It does cost $15, but I think it's worth it. FYI, I have no association with the app developer