Yes, you really can make free phone calls using the internet. The apps I'll mention come in two types: Some only work if the other person has the same app, while others let you call any number ...
1. Open the Settings app on your device. 2. Tap "Networks & Internet" or "Connections," depending on your Android device. 3. Tap "Mobile network." Depending on your device, "Wi-Fi Calling" may be ...