The permission of "app.permission.RECORD_AUDIO" is to record and play the sound of users, increase the interest of graphical programming.
The permission of "app.permission.WRITE_EXTERNAL_STORAGE" and ”app.permission.READ_EXTERNAL_STORAGE" is to save the building instructions that users download.
The permission of "app.permission.READ_PHONE_STATE" is used for Baidu SDK, in order to convert text into voice.