You have a weather station and a web server (i.e. Raspi - Raspberry Pi), which can provide these weather data to the world wide web. You know how the weather behaves better than others. You are searching for a nice app + widget that can bring your data to your mobile phone which is automatically updated in backround?
The app Home Weather for Android is the solution.
The app "Home Weather" uses permission which are needed for functionality only.
Die App "Heimat Wetter" verwendet nur Rechte welche für die Funtion benötigt werden.
No data is collected. No data is transferred to anywhere.
Es werden keine Daten aus dem Gerät erhoben. Es werden keine Daten weitergegeben.
If the server access shall be done protected (https) and a certificate with a CA signature is not available, a self signed certificate can be used. How this can be setup is described in application note HTTPS with self signed certificate on Android
The application note no Domain - use of ownDNS describes the functionality, setup and use of ownDNS if you want to use this app built in function.