Ways to share common data in Android app?

How to share state/data across several Activities and all parts of application?

I have found few ways to achieve this after some research:

1. Class with data (for example POJO that contains user data) to share must become Singleton and is called like this:

class MyActivity extends Activity {
  ...

@Override
public void onCreate(...){
  super.onCreate();
  // user is initialised somewhere else  
  final User user = User.instance();
  final String username = user.name();
}

2. Class with data becomes static member of Application class

class App extends Application { 
  private static User sUser;

  public static User currentUser() {
    return sUser;
  }

//usage:
...
final User user= App.currentUser();
...

3. Class with data becomes field of Application class

class App extends Application { 
  private User sUser;

  public User currentUser() {
    return sUser;
  }

//usage:
...
final User user= ((App)getApplicationContext()).currentUser();
...

3. Class with data is injected using some DI framework (Dagger, Koin, etc.)
4. I have created apps using React Native and Redux architecture, so I think Redux can be used in Android somehow too?

Which way do you prefer? What are the pros and cons of each way above?
Thank you for your feedback!