Central topic for questions/discussing the SIEGENIA App. You can use this topic to ask questions and share your experiences with the devices from SIEGENIA.
This app is developed by @Doekse and supports the new SIEGENIA Matter devices. For support use the e-mail link on the Homey App Store page. Support Contact »
Hi @Doekse,
Why is the app needed? The smart window handle from SIEGENIA uses Matter as protocol. And Matter devices don’t actually need an additional Homey app, afaik.
The RAM of a Homey Pro (early 2023) / Homey Pro mini isn’t infinite. So we’re actually happy that we don’t need a separate Homey app for every (Matter) device.
Matter apps exist to make products easier to find in the Homey App Store. We’ve noticed that many customers contact support after purchasing a Matter-compatible device because they can’t find the brand listed in the store. These apps also provide helpful quality-of-life features, such as custom device icons and pairing instructions.
That said, you don’t need to install the app to use the product, it’s completely optional 
About a month ago, I added a Lafaer LWR01 presence sensor via Devices → + → New Device → Technology → Matter. I hadn’t installed the Homey Lafaer app beforehand, but the app was installed automatically during the adding process. As far as I can remember, I wasn’t given any options or asked whether I wanted to install the Homey Lafaer app or not. Therefore, in my opinion, it’s not optional.
What happens if I delete the app now? Will the sensor be automatically deleted as well?
It would be useful if, when adding a Matter device, you were asked whether you wanted to install the optional Homey app as well.
In addition, it would be helpful to compare the functional differences between adding the device with or without the optional Homey app. Ideally, this would be done during the adding process, but at the very least in the Homey App Store.
This should already happen;
You can choose if you want to install the app or just go ahead and install the device without the app
Okay, that’s great, then I really couldn’t remember it anymore.
But then there is still the point about functional differences…
Edit
Just a short update, @Doekse.
I’ve added the LWR01 without the Homey Lafaer App. Except for the missing original device icon, I didn’t find any differences when I briefly looked at it, neither in terms of function nor in terms of settings options.
However, both variants use the capability alarm_motion instead of alarm_presence or alarm_occupancy, even though, according to the Matter info, occupancy_sensor is supported as a device type:
