A simple which alerts you before the blue circle appears.
You can also see the lowest your health can be before healing in the blue circle.
The settings page allows you to edit the alert / circle timers and heal times.
Version history
1.4
2018-07-20
This app has been updated by Apple to display the Apple Watch app icon.
Fixed issues with sound on some devices.
Fixed bugged font in some locations.
Fixed plus and minus buttons so that they now work correctly.
1.3
2018-05-17
Added run speed during blue zone.
Added changeable time increments for the + and - buttons.
To change the time increment, click the current increment or the current game time.