diff --git a/.gitignore b/.gitignore
index 9938cbc..6b7cc2b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,15 +1,133 @@
+# Miscellaneous
+*.class
+*.lock
+*.log
+*.pyc
+*.swp
 .DS_Store
-.dart_tool/
+.atom/
+.buildlog/
+.history
+.svn/
+
+# IntelliJ related
+*.iml
+*.ipr
+*.iws
+.idea/
+
+# Visual Studio Code related
+.classpath
+.project
+.settings/
+.vscode/*
 
+# Flutter repo-specific
+/bin/cache/
+/bin/internal/bootstrap.bat
+/bin/internal/bootstrap.sh
+/bin/mingit/
+/dev/benchmarks/mega_gallery/
+/dev/bots/.recipe_deps
+/dev/bots/android_tools/
+/dev/devicelab/ABresults*.json
+/dev/docs/doc/
+/dev/docs/flutter.docs.zip
+/dev/docs/lib/
+/dev/docs/pubspec.yaml
+/dev/integration_tests/**/xcuserdata
+/dev/integration_tests/**/Pods
+/packages/flutter/coverage/
+version
+analysis_benchmark.json
+
+# packages file containing multi-root paths
+.packages.generated
+
+# Flutter/Dart/Pub related
+**/doc/api/
+.dart_tool/
+.flutter-plugins
+.flutter-plugins-dependencies
+**/generated_plugin_registrant.dart
 .packages
+.pub-preload-cache/
 .pub/
-
 build/
-ios/.generated/
-ios/Flutter/Generated.xcconfig
-ios/Runner/GeneratedPluginRegistrant.*
+flutter_*.png
+linked_*.ds
+unlinked.ds
+unlinked_spec.ds
 
-.idea
+# Android related
+**/android/**/gradle-wrapper.jar
+.gradle/
+**/android/captures/
+**/android/gradlew
+**/android/gradlew.bat
+**/android/local.properties
+**/android/**/GeneratedPluginRegistrant.java
+**/android/key.properties
+*.jks
 
-*.iml
-pubspec.lock
\ No newline at end of file
+# iOS/XCode related
+**/ios/**/*.mode1v3
+**/ios/**/*.mode2v3
+**/ios/**/*.moved-aside
+**/ios/**/*.pbxuser
+**/ios/**/*.perspectivev3
+**/ios/**/*sync/
+**/ios/**/.sconsign.dblite
+**/ios/**/.tags*
+**/ios/**/.vagrant/
+**/ios/**/DerivedData/
+**/ios/**/Icon?
+**/ios/**/Pods/
+**/ios/**/.symlinks/
+**/ios/**/profile
+**/ios/**/xcuserdata
+**/ios/.generated/
+**/ios/Flutter/.last_build_id
+**/ios/Flutter/App.framework
+**/ios/Flutter/Flutter.framework
+**/ios/Flutter/Flutter.podspec
+**/ios/Flutter/Generated.xcconfig
+**/ios/Flutter/ephemeral
+**/ios/Flutter/app.flx
+**/ios/Flutter/app.zip
+**/ios/Flutter/flutter_assets/
+**/ios/Flutter/flutter_export_environment.sh
+**/ios/ServiceDefinitions.json
+**/ios/Runner/GeneratedPluginRegistrant.*
+
+# macOS
+**/Flutter/ephemeral/
+**/Pods/
+**/macos/Flutter/GeneratedPluginRegistrant.swift
+**/macos/Flutter/ephemeral
+**/xcuserdata/
+
+# Windows
+**/windows/flutter/generated_plugin_registrant.cc
+**/windows/flutter/generated_plugin_registrant.h
+**/windows/flutter/generated_plugins.cmake
+
+# Linux
+**/linux/flutter/generated_plugin_registrant.cc
+**/linux/flutter/generated_plugin_registrant.h
+**/linux/flutter/generated_plugins.cmake
+
+# Coverage
+coverage/
+
+# Symbols
+app.*.symbols
+
+# Exceptions to above rules.
+!**/ios/**/default.mode1v3
+!**/ios/**/default.mode2v3
+!**/ios/**/default.pbxuser
+!**/ios/**/default.perspectivev3
+!/packages/flutter_tools/test/data/dart_dependencies_test/**/.packages
+!/dev/ci/**/Gemfile.lock
+!.vscode/settings.json
\ No newline at end of file
diff --git a/example/android/.gitignore b/example/android/.gitignore
deleted file mode 100644
index 0a741cb..0000000
--- a/example/android/.gitignore
+++ /dev/null
@@ -1,11 +0,0 @@
-gradle-wrapper.jar
-/.gradle
-/captures/
-/gradlew
-/gradlew.bat
-/local.properties
-GeneratedPluginRegistrant.java
-
-# Remember to never publicly share your keystore.
-# See https://flutter.dev/docs/deployment/android#reference-the-keystore-from-the-app
-key.properties
diff --git a/example/ios/.gitignore b/example/ios/.gitignore
deleted file mode 100644
index 2a8c8b6..0000000
--- a/example/ios/.gitignore
+++ /dev/null
@@ -1,44 +0,0 @@
-.idea/
-.vagrant/
-.sconsign.dblite
-.svn/
-
-.DS_Store
-*.swp
-profile
-
-DerivedData/
-build/
-GeneratedPluginRegistrant.h
-GeneratedPluginRegistrant.m
-
-.generated/
-
-*.pbxuser
-*.mode1v3
-*.mode2v3
-*.perspectivev3
-
-!default.pbxuser
-!default.mode1v3
-!default.mode2v3
-!default.perspectivev3
-
-xcuserdata
-
-*.moved-aside
-
-*.pyc
-*sync/
-Icon?
-.tags*
-
-/Flutter/app.flx
-/Flutter/app.zip
-/Flutter/flutter_assets/
-/Flutter/App.framework
-/Flutter/Flutter.framework
-/Flutter/Generated.xcconfig
-/ServiceDefinitions.json
-
-Pods/
diff --git a/example/ios/Flutter/flutter_export_environment.sh b/example/ios/Flutter/flutter_export_environment.sh
deleted file mode 100755
index 8d16d51..0000000
--- a/example/ios/Flutter/flutter_export_environment.sh
+++ /dev/null
@@ -1,13 +0,0 @@
-#!/bin/sh
-# This is a generated file; do not edit or check into version control.
-export "FLUTTER_ROOT=C:\Users\wenyeh\flutter"
-export "FLUTTER_APPLICATION_PATH=D:\Flutter Project\rect_getter\example"
-export "COCOAPODS_PARALLEL_CODE_SIGN=true"
-export "FLUTTER_TARGET=lib\main.dart"
-export "FLUTTER_BUILD_DIR=build"
-export "FLUTTER_BUILD_NAME=1.0.0"
-export "FLUTTER_BUILD_NUMBER=1"
-export "DART_OBFUSCATION=false"
-export "TRACK_WIDGET_CREATION=true"
-export "TREE_SHAKE_ICONS=false"
-export "PACKAGE_CONFIG=.dart_tool/package_config.json"
diff --git a/example/linux/flutter/generated_plugin_registrant.cc b/example/linux/flutter/generated_plugin_registrant.cc
deleted file mode 100644
index e71a16d..0000000
--- a/example/linux/flutter/generated_plugin_registrant.cc
+++ /dev/null
@@ -1,11 +0,0 @@
-//
-//  Generated file. Do not edit.
-//
-
-// clang-format off
-
-#include "generated_plugin_registrant.h"
-
-
-void fl_register_plugins(FlPluginRegistry* registry) {
-}
diff --git a/example/linux/flutter/generated_plugin_registrant.h b/example/linux/flutter/generated_plugin_registrant.h
deleted file mode 100644
index e0f0a47..0000000
--- a/example/linux/flutter/generated_plugin_registrant.h
+++ /dev/null
@@ -1,15 +0,0 @@
-//
-//  Generated file. Do not edit.
-//
-
-// clang-format off
-
-#ifndef GENERATED_PLUGIN_REGISTRANT_
-#define GENERATED_PLUGIN_REGISTRANT_
-
-#include <flutter_linux/flutter_linux.h>
-
-// Registers Flutter plugins.
-void fl_register_plugins(FlPluginRegistry* registry);
-
-#endif  // GENERATED_PLUGIN_REGISTRANT_
diff --git a/example/linux/flutter/generated_plugins.cmake b/example/linux/flutter/generated_plugins.cmake
deleted file mode 100644
index 2e1de87..0000000
--- a/example/linux/flutter/generated_plugins.cmake
+++ /dev/null
@@ -1,23 +0,0 @@
-#
-# Generated file, do not edit.
-#
-
-list(APPEND FLUTTER_PLUGIN_LIST
-)
-
-list(APPEND FLUTTER_FFI_PLUGIN_LIST
-)
-
-set(PLUGIN_BUNDLED_LIBRARIES)
-
-foreach(plugin ${FLUTTER_PLUGIN_LIST})
-  add_subdirectory(flutter/ephemeral/.plugin_symlinks/${plugin}/linux plugins/${plugin})
-  target_link_libraries(${BINARY_NAME} PRIVATE ${plugin}_plugin)
-  list(APPEND PLUGIN_BUNDLED_LIBRARIES $<TARGET_FILE:${plugin}_plugin>)
-  list(APPEND PLUGIN_BUNDLED_LIBRARIES ${${plugin}_bundled_libraries})
-endforeach(plugin)
-
-foreach(ffi_plugin ${FLUTTER_FFI_PLUGIN_LIST})
-  add_subdirectory(flutter/ephemeral/.plugin_symlinks/${ffi_plugin}/linux plugins/${ffi_plugin})
-  list(APPEND PLUGIN_BUNDLED_LIBRARIES ${${ffi_plugin}_bundled_libraries})
-endforeach(ffi_plugin)
diff --git a/example/pubspec.yaml b/example/pubspec.yaml
index 34e069a..fb09945 100644
--- a/example/pubspec.yaml
+++ b/example/pubspec.yaml
@@ -2,7 +2,7 @@ name: example
 description: A new Flutter application.
 
 environment:
-  sdk: ">=2.12.0 <3.0.0"
+  sdk: ">=2.12.0 <4.0.0"
 
 dependencies:
   flutter:
diff --git a/pubspec.yaml b/pubspec.yaml
index c6bd8f8..f57fb1a 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -12,7 +12,7 @@ dev_dependencies:
     sdk: flutter
 
 environment:
-  sdk: ">=2.12.0 <3.0.0"
+  sdk: ">=2.12.0 <4.0.0"
 
 # For information on the generic Dart part of this file, see the
 # following page: https://www.dartlang.org/tools/pub/pubspec