This is the full code sample used in my "Flutter Dismissible (Swipe Left)" example on Instagram.

Flutter - Dismissible (Swipe Right)

import 'package:flutter/material.dart';

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

class ExampleApp extends StatelessWidget {
  final items = List<String>.generate(20, (i) => "Swipe To The Right");

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: ListView.builder(
          itemCount: items.length,
          itemBuilder: (context, index) {
            final item = items[index];

            return Dismissible(
              key: Key(item),
              background: Container(
                alignment: AlignmentDirectional.centerStart,
                color: Color(0xff8fc3ff),
                child: Padding(
                  padding: EdgeInsets.fromLTRB(0.0, 0.0, 10.0, 0.0),
                  child: Row(
                    children: [
                      Padding(
                        padding: EdgeInsets.fromLTRB(10.0, 0.0, 5.0, 0.0),
                        child: Icon(
                          Icons.mail,
                          color: Colors.white,
                          size: 18.0,
                        ),
                      ),
                      Text(
                        'Unread',
                        style: TextStyle(
                          fontSize: 14.0,
                          color: Colors.white,
                        ),
                      ),
                    ],
                  ),
                ),
              ),
              direction: DismissDirection.startToEnd,
              child: Container(
                decoration: BoxDecoration(
                  border: Border(
                    bottom: BorderSide(
                      color: Colors.grey,
                    ),
                  ),
                ),
                child: ListTile(
                  title: Text('$item'),
                ),
              ),
            );
          },
        ),
      ),
    );
  }
}