As the first version of an app launched on store, it requires a support in terms of update. Updates can be available on store quarterly depending on popularity of an application.
With every new update of app, new features are getting involved. Also bugs from previous install get resolved. Thus updating app will provide complete bug-free experience.
One another thing behind updates is that, OS versions and development tools are improving themselves regularly. So new features and ease of access tools getting added to OS platforms. To support these new features, app should be updated to support that OS.
With updates developers can control versioning and phases of app. So that user knows the new things that are involved by looking at the release notes.
How Would You Know When Your App Needs A Major Update?
As soon as developer uploads new app with version on store, user gets notified via push notification. User gets a message of telling that new updates are available for this app.
Application updates mainly focused on solving bugs and adding small features. Major updates include a brand new UI with great visual experience and new features.