Playing Stardew Valley Co-op Without Internet
When using your iPhone's Personal Hotspot, Stardew still connects to the master server.
Use this trick to use your Personal Hotspot as a local only LAN hub to play games like Stardew Valley without internet connection.
1. Enable Personal Hotspot and connect
2. Open Wifi-Settings & Details
3. Get the Router IP address
4. Use that IP to connect
And this is how you can use your iPhone to play with your friends without any internet connection.