Todo List App

A cross-platform Todo List App created using Dart and Flutter. I followed the tutorials by Johannes Mike for personal learning. Then started tinkering with the app to customize it and learn more about Flutter.

Flutter Setup


Follow the instructions on offical website, depending on your operating system. In my case I am using Windows.

  • Download and install JDK from the link
  • Install Git
  • Download the latest stable release of the Flutter SDK
  • Extract the zip file and place the contained flutter in the desired installation location for the Flutter SDK.
  • Warning: Do not install Flutter in a directory like C:\Program Files\ that requires elevated privileges.
  • Add flutter\bin to your PATH environment variable
  • Download and install Android Studio and VS Code
  • Install Android SDK Tools and Google usb driver from Android Studo’s SDK Mnagaer
  • Install FLutter and Dart extensions in VS Code.
  • Setup an emulator in AVD Manager inside Android Studio to run your apps in a virtual device. Alternatively, you can also use a real device.

Firebase Setup

Steps for android

  • Create a new project on you firebase account
  • Then create an android app
  • Find package name at android/app/main/src/build.gradle and look for applicationID
  • Register the app
  • Add the Firebase Android configuration file to your app:
  • Click Download google-services.json to obtain your Firebase Android config file.
  • Move your config file into the module (app-level) directory of your app.
  • In your root-level (project-level) Gradle file (build.gradle), add rules to include the Google Services Gradle plugin. Check that you have Google’s Maven repository, as well.

dependencies {
    // ...

    // Add the following line:
    classpath ''  // Google Services plugin
  • In your module (app-level) Gradle file (usually app/build.gradle), apply the Google Services Gradle plugin:

apply plugin: ''
// Add the following line:
apply plugin: ''  // Google Services plugin

android {
  // ...
  • Declare the dependencies for the Firebase products that you want to use in your app. Declare them in your module (app-level) Gradle file (usually app/build.gradle).

dependencies {
  // ...
  // Declare the dependency for the Firebase SDK for Google Analytics
  implementation ''
  • Click Next

Steps for iOS

  • In flutter, bundle id is same as product name for the android case. However you can ge tit by opening iOS fodler in Xcode. Select Runner and then General tab. Copy your Bundle Identifier and paste in the browser.
  • Enter the information and register app
  • Click Download GoogleService-Info.plist to obtain your Firebase Apple platforms config file.
  • Drag this file inside Runner/Runner folder. Make sure Add to targets is ticked.
  • Next go to iOS\Podfile. Change iOS platfrom to 10.0. If you don’t have the Podfile, it can be generated by flutter run or by pod init command.
  • In you browser, click Next multiple times and then continue to console.


App functionality

  • Add, Edit and Delete tasks
  • Colorful widgets
  • Local plus cloud storage using firebase

Resolving Issues

In case you run into some build issues after copying your project among different devices or after some package updates, try the following steps before anything else.
Run following command in root directory.

flutter clean
flutter pub get
flutter run

Unsound safety check

Some packages give unsound safety check issue if you have older versions of firebase plugins. Reolve this by adding
–no-sound-safety-check argument to your run command.

flutter run --no-sound-safety-check

Running on iOS

  • iOS run needs Podile. It will be generated automatically after Flutter run.
  • If xcode doesn’t work (in general or in copied project), remove ios/Podfile (lockfile and pods as well)

Then run in the root project directory.

flutter clean
flutter pub get
flutter run


If you see the error "issue: I/Process ( 5084): Sending signal. PID: 5084 SIG: 9", then do the following to resolve it.

  • Open android/app/build.gradle
  • Inside dependies list, add implementation "io.grpc:grpc-okhttp:1.32.2"

dependencies {
    implementation "io.grpc:grpc-okhttp:1.32.2"

Version Issue


  • ADD to Podfile:

post_install do |installer|
  installer.pods_project.targets.each do |target|
      target.build_configurations.each do |config|
         if config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'].to_f < 10.0
           config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = '10.0'

MigratMigration to cloud_firestore 2.0.0

  • The migration involves adding a <Map<String, dynamic>> in numerous places
  • Do it only if you use newer versions of firebase_core and cloud_firestore


- StreamBuilder<DocumentSnapshot>(
+ StreamBuilder<DocumentSnapshot<Map<String, dynamic>>>(
  stream: FirebaseFirestore.instance.collection('movies').doc('star-wars').snapshots(),
-  builder: (BuildContext context, AsyncSnapshot<DocumentSnapshot> snapshot) {
+  builder: (BuildContext context, AsyncSnapshot<DocumentSnapshot<Map<String, dynamic>>> snapshot) {
    // ...

My Case

  • Change tranbsformer in utils.dart from

static StreamTransformer<QuerySnapshot, List<T>> transformer<T>(
      T Function(Map<String, dynamic> json) fromJson) =>
  StreamTransformer<QuerySnapshot, List<T>>.fromHandlers(
    handleData: (QuerySnapshot data, EventSink<List<T>> sink) {
      final snaps = =>;
      final users = => fromJson(json)).toList();



  static StreamTransformer<QuerySnapshot<Map<String, dynamic>>, List<T>>
      transformer<T>(T Function(Map<String, dynamic> json) fromJson) =>
          StreamTransformer<QuerySnapshot<Map<String, dynamic>>,
            handleData: (QuerySnapshot data, EventSink<List<T>> sink) {
              final snaps = =>;
              final users = snaps
                  .map((json) => fromJson(json as Map<String, dynamic>))


Debug mode issue on <= iOS 14

While debugging/running on devices with iOS 14 or less, the app stopped working as soon as the program is terminated in the IDE. To resolve it, add --release to your flutter run command.

flutter run --release --no-sound-null-safety


Special thanks to Johannes Mike for his amazing youtube tutorial and repository.

Johannes’s Youtube Tutorials:


View Github