How to be sure my app will not be rejected on the App Store?
To be sure your app will be validated by Apple you have some things to know (for Android’s Google Play there is a validation too now but, it’s more permissive): All your pages have to be filled out with content. Please be sure you have no empty pages. If you have a...Update app without a new publication
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,...