There aren't many recent posts about the Controller app for HomeKit on iOS. I thought I'd do a quick review here based on a few days with the app.

Is $29.99 a year worth it? I think that depends on how you are set up. For me, it's worth it since my setup is HomeKit with most devices using Thread transport. I don't even have a Matter device yet. I rely on Home.app for all my automations. I have the Eve app, but I don't use it for anything other than inspecting my Thread network. I don't even have a large WiFi load. From what I've read, you probably don't need or want this app if most of your automations use a vendor app for HomeKit integration. My smart devices are ecobee (thermostats and buzzer), Eve (sockets and light switch), Schlage and Wemo (sockets), the last 3 being on Thread transport. They all have their own apps that interface with HomeKit. Hubs are Apple TV and HomePod Mini. Everything I buy going forward will be Thread to the fullest extent possible.

Some key features in the Controller app. For system maintenance, it allows backups of automations and storage of configuration codes. The app shines with improved automation control. A lot of my automations are lighting and sunset related. The Controller app allows automations to have multiple condition statements that allow for a full range of mixing and matching well beyond what Home.app does natively. I won't go into too much of my automations, but the Controller app really opens up a robust interface to build useful automations. I think the app is worth the cost for that reason alone. The Controller app has a very powerful recording feature, which is very useful if you have automations based on motion detection. The controller lets you explore any piece of data your devices report to HomeKit. With my ecobee thermostats and sensors, I can see very granular temperature data in the Controller that I can't see in the ecobee app or anywhere else.