You can check the battery status of your phone and your watch with your watch.
Complication is supported (automatic update).
You can check the charging amount of the your phone and the state of charge timely from the dial of the clock.
I will notify you by notice when the charge amount of your phone or your watch becomes less than the specified%.
Please set complication with your phone's watch application or you watch settings app.
Battery status displayed in complication is automatically updated approximately every 30 minutes.
As soon as you start BatteryWatch from complication, you can check the latest status.
Circular complications can assign the remaining battery indication of your phone and your watch to the outer circle and the inner number respectively.
The automatic update every 30 minutes is the iOS specification.
Thank you for your understanding.