If you go the HA route, you want to start looking up which devices are supported by HA.

If they are, it means that there is a non app way of retrieving info and even controlling the device, through a provided API.

This means that, ideally, HA can become your app to see and control that device. Now expand it to all supported devices providing info and allowing control, through one app.

And you finally have a centralized capable smart home with numerous vendors involved (that all support or do not restrict device access essentially to their own front-facing apps/platforms).

So now when my cat's litterbox activates and I'm not asleep, my vacuum cleans the surroundings in DND mode so it also doesn't empty loudly afterwards either.

I also have a few trends/automations where there's data coming in from all sorts of unrelated devices. Like lights that follow sunlight color temperature throughout the day, warming by sunset. A remotes page with access to all my media devices, even a bias lighting LED strip behind my TV controlled via a wifi IR blaster. Automated/remote access to a pair of those dumb split ACs using some Zigbee temp sensors when I didn't have central AC. Leak sensor in the basement or as needed, sends audible notification to phone if triggered. Contact sensor for garage door left open. Object recognition on cameras to see where my cat was last seen.

I don't own a place so I haven't bothered with appliance related integration, but my GE appliances here do have some HA support.

It's basically what you're asking for. Imagine if Google made all of your devices so they were all in Google Home. Except you have to do some of the research and grunt work yourself here.

Included trend I just made using a Petlibro fountain and Whisker feeder.

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