Yes. And without any new app submission process. Your app is automatically up to date.
The only things you can't modify on your apps without a new submission are : app icon, push icon for Android, app startup image (splash screen), app name, app description, categories and keywords, the mobile website url. If you add the Places/Directory feature while your app is already published, it will not work and your app will need to be republished. Another point concerns the "audio" and "radio" features: if you want them to work with multitasking (navigate through your phone, outside your app, with music keep on playing), you have to integrate them on your first publishing, if your app is already published when you add these features, they won't work in multitasking mode, and you will have to submit again if you want them to work in multitasking.
Design, logo (not app icon, just the logo in the news wall feature), colors and of course features are editable when you want and as many times as you need.
Furthermore, if you want to change the screenshots of your app on the App Store, the app must be resubmitted.
A new submission process due to your mistake/omission for exemple because you want to change the app icon, splash screen, or if you want to add multitasking on "audio" and "radio" feature, will cost you 39€ for IOS and Android, 29€ for IOS only, and 19€ for Android only.