fritz platform offers presence detection by looking at connected devices to a AVM Fritz!Box based router.
It might be necessary to install additional packages:
$ sudo apt-get install python3-lxml libxslt-dev libxml2-dev zlib1g-dev
If you installed Home Assistant in a virtualenv, run the following commands inside it:
$ pip3 install lxml; be patient this will take a while.
To use an Fritz!Box router in your installation, add the following to your
# Example configuration.yaml entry device_tracker: - platform: fritz
(string)(Optional)The IP address of your router, e.g.,
192.168.1.1. It is optional since every fritzbox is also reachable by using the IP address 169.254.1.1.
(string)(Optional)The username of an user with administrative privileges, usually
(string)(Optional)The password for your given admin account.
It seems that it is not necessary to use the password in current generation Fritz!Box routers because the necessary data can be retrieved anonymously.
See the device tracker component page for instructions how to configure the people to be tracked.