1. Start APKit
2. Select the app you want to copy to external storage
3. Tap the drop down menu from top right
4. Tap 'Share Package(APK) File(s)' option.Choose the first option ('External Storage')
5. Tap 'Apply'. The APK file of the app will be copied to the external folder and confirmation message will be shown
6. You can now connect you device to a computer via USB and access the APK file