Change App Name

Android

Open the file AndroidManifest.xml under android--> app --> src --> main. Enter the preferred app name in the label under application tag.

<application
        android:label="Enter Your Desired Name Here" 
        android:name="${applicationName}"
        android:requestLegacyExternalStorage="true"
        android:icon="@mipmap/launcher_icon">

iOS

For iOS, change the name for CFBundleDisplayName as shown in image below.