To allow Battery Health 3 to access your iOS device over WiFi, please open iTunes on your Mac and select your iOS device. Then enable the “Sync with this iPhone / iPad over Wi-Fi" option. Finally, press the 'Done' button.
Please note that you will need to unlock your phone when prompted and that Battery Health 3 will only be able to access your device battery information when it is turned on and unlocked.
To connect over USB, simply connect your iOS device to your Mac and give permission for your Mac to communicate with your device.
After you have connected your iOS device, select from the drop down menu on Battery Health 3, the iOS device you want to view: