The smart home features in our apartment were controlled by an overly engineered app, called Dwelo. At the time it didn't feel like they put much thought into the design and functionality. The app was slow and difficult to use. There were features that I wanted that just didn't exist. The designer kept it simple though, which I liked a lot.
This part was easy, make a mobile interface that could do a lot of complex things, that didn't also look engineered. Looking back, I would do this way differently. But the outcome ended up being a decent, simple-to-use, app that could control the smart features in my apartment. I sent the designs to Dwelo, and they didn't make it past customer support. I think I was too arrogant at the time.