How to change Android App Name and ID of an existing application?
Actually you need to change the name in several places:
First, as you said, the name of the string, which is the visible name of the application.
Second, go to activity->src and right click on the package (com.example.whatever) and do refactor->rename;
Then go to the manifest.xml: and change the field in:
<manifest package="com.example.whatever" >
If you are using native code, JNI, you will also have to change the names of the c++ functions, which is a pain in the ass:
Java_com_example_whatever_activity_function()
For those who aren't using Android Studio and want to do it manually (e.g. if you're using React Native), I just recently went through this and had to change it in the following files:
index.android.js
android/settings.gradle
android/app/build.gradle
android/app/src/main/AndroidManifest.xml
android/app/src/main/java/com/<app id>/MainActivity.java
android/app/src/main/java/com/<app id>/MainApplication.java
Package name (in java).
The app name is also in the manifest, although I don't think that needs to be unique, but still would be good to change it for clarity.