change app name in App Store

Direct quote from Apple's documentation:

You can change the name of your existing app only when submitting an update of your app binary. If you submit an app name which is already in use within the same geography in which your app is sold, you will be prompted to enter another name.

I just googled it.

The name of the app as it appears on the app store is entered when submitting a new or updated app binary. The app name is not actually configured inside the app binary itself. Hope that is clear. If you want to change the launcher name as it appears below the icon in iOS, then you can change that in your actual project configuration.

If you have already created the new version in ITC, you can edit your apps name with the following steps:

In iTunes Connect, click your app and you will see versions at the bottom of the page, click "View Details" of your updated version (e.g. 1.1).

Then click "Edit" next to "Metadate and Upoads"

In the pop-up change the text in the field "App Name"