Hey, I don't think we should integrate this specific evaluation as a separate sensor. This is a value generated from other values provided by this integration. I think a better approach would be to use a template sensor to get the number of connected wifi devices, try something like this:

{{ states.device_tracker|selectattr('state', 'eq', 'home')|selectattr('attributes.type', 'ne', 'lan')|list|length }}

Ok I can try that.
I think I saw it on the fritzbox integration, but let me double check :)

Ah I see here some information :)
https://www.home-assistant.io/integrations/fritz/

IMHO this could be useful, off course there are workarounds e.g. for the QR image I just safed it manually from the speedport.ip. But if I change it again, I also have to manually update it :)

• Update - firmware status of the device.
• Image - QR code for Guest Wi-Fi.
• Device tracker - presence detection by looking at connected devices.

It's no high priority but some ideas for long term.

{{ states.device_tracker|selectattr('state', 'eq', 'home')|selectattr('attributes.type', 'ne', 'lan')|list|length }}

I tried this, but it's not complete the same. Here I have 46 devices connected.
My Speedport status show me 49 connected devices.
I haven't been able to figure out which 3 devices are missing yet.