Hello,
At the moment Zoiper does not support hotspot preferences, however it is in our to-do list for the future releases.
Could you please tell us more about:
- how did you discover that it is zoiper that is draining your battery?
- what is the exact version of Zoiper that you are using?
- what are the brand and model of your android device?
- do you completely exit Zoiper, or do you just unregister the account?