1. How to change volume ?
Depend your device, you can configure the volume of recording in setting screen.
2. Where is my record file save ?
Recording files was save to Hatkara folder in your device Menu -> Record List
3. How to share record file to facebook, zalo ?
B1. Upload your record file to google drive
Menu -> Record List -> click record file -> click button share -> choose Drive B2. Open Google Drive, share file saved before.
4. How to change voice ?
Menu -> settings -> sample rate