Simple battery level data field, plain look, with fit file logging.
https://apps.garmin.com/en-US/apps/c0797db5-6570-4db1-b7fc-474b1c51cebf
This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.