How to check if there is an update in Android OS using Flutter

Yes you can use upgrader for this

import 'package:flutter/material.dart';
import 'package:upgrader/upgrader.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  const MyApp({Key key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Upgrader Example',
      home: Scaffold(
          appBar: AppBar(title: Text('Upgrader Example')),
          body: UpgradeAlert(
            child: Center(child: Text('Checking...')),
          )),
    );
  }
}