@djandib not only.
The implementation (as i understand it) behind: Pulsestation make an http request for your configured ip adress.
So just open a browser and try http://[YOUR-IP]:[YOURPORT]
in case you got any result (200 response) then you computer/android device is running. otherwise not.
Thats why you need to have any WebServer running. Under Windows 7/10 the simplest one is Internet Information Service from Microsoft themself.