I’d like to know the transmission of SE Android app is encrypted or not with https. Please make me confirm.
The app is using the Stack Exchange API, which requires HTTPS to be used whenever a user access token is transmitted.
I did an inspection of traffic to/from my phone, and confirmed the app does connect to a Stack Exchange IP address (188.8.131.52) over HTTPS whenever a network based action is taken.
But, I don't have access to the app source code so I can't be 100% sure. As far as I can tell, all network traffic related to the app is handled via secure tunnels. Including the push notifications which go through Google's servers.