foreground_service (Flutter v.1.12.x or later)

Create Android foreground service/notification

Prep (Android side):

Android foreground services require a notification to be displayed,
and notifications require an icon.

For this plugin to work, the icon needs to be in this specific location:

res/drawable/org_thebus_foregroundserviceplugin_notificationicon

(take a look at the /example app if you're confused)

Use (Flutter/Dart side):

To start the service, call ForegroundService.startForegroundService([serviceFunction])

serviceFunction will then be executed periodically, but "minimum/best-effort"
i.e. it will try to make the interval between function executions *at least* that long

Doesn't work?

As long as you're calling ForegroundService.startForegroundService,
"flutter run" should show error messages that indicate what's wrong/missing

i.e. messages beginning with E/ForegroundServicePlugin indicate an error from the plugin

Caution:

ForegroundService.notification.get* methods may give unexpected values.

Once notifications are sent out, there's no way to retrieve the "current" data.

To work around this, the plugin keeps a version of the notification around.
This version may not have been "sent out" yet, however.

Disclaimer:

Most of the fancy stuff is shamelessly pilfered from the android_alarm_manager plugin