Get the installed packages list:
adb shell pm list packages
Get the path of the package ( for example com.example.app):
adb shell pm path com.example.app
Download the apk:
adb pull full_path
Download apk from device via ADB
Get the installed packages list:
adb shell pm list packages
Get the path of the package ( for example com.example.app):
adb shell pm path com.example.app
Download the apk:
adb pull full_path