Yes. Your app is automatically updated with your new content, as well as new colors and new design options.
The only things that would require new submissions are items related to the app itself:
- app icon
- app startup image (splash screen)
- app name
- app description (only for the App Store)
- categories and keywords (only for the App Store)
- the web app url (in Settings > Domain), if you change it after your app is published
- adding certain features/modules (if after adding a new feature to your app, the feature does not open in your app, the app must be republished)
To make sure that your app is updated when you add changes to it, just “kill” your app and launch it again twice (there is a delay of about 1 minute so that it is updated) and your app will be up to date.
If you add new features in your app after it has been published, these features would require to submit the app again if you don’t have added them before publishing:
- Audio & Radio features (you can add them after your app is published but it will not work in background mode when the app is closed)
- AdMob for iOS (For Android you can add AdMob banners or interstitials after your app is published, but iOS will need new publication)
Furthermore, after some updates, all apps requiring features & fixes from this update and after must be republished. This is always mentioned in the release note of the updates.
But, adding or changing content to these features after your app has been published doesn’t require to publish again.