>>821
どうやら「flutter_local_notifications 」パッケージを使った方がよさげな模様。
これなら、AndroidだけじゃなくiOSもいけるっぽい。

ttps://ichi.pro/flutter-no-tsuchi-to-ara-mu-41660884726638
ttps://stackoverflow.com/questions/61905143/how-to-create-alarm-app-in-flutter-for-ios
https://pub.dev/packages/flutter_local_notifications