AutoBluetooth, being an installed app, can be in reach of some of your personal information. Those information are used ONLY to provide a service to you and won't be in any way transmitted or sold.
AutoBluetooth needs several Android authorizations to properly work. Even if those open possibilities of reading and sending your personal information, like your addresses, wifi networks, call logs, etc, such activities are not performed.
As an example, if a required authorization permits reading your call log this may be not read at all by AutoBluetooth. It is possible that the same authorization allows other simple tasks that are instead used by the app. In ANY case no info is transmitted.
Autobluetooth uses advertising as form of revenue generator. Admob is used as ad platform. With latest Google Play Services Admob is shipped to devices. Latest versions provide an anonymization mechanism that makes impossible for anyone (Google included) to associate behaviours to a physical person, saving personal privacy.
Moreover Google implemented a mechanism that resets the user information stored for ad targeting. Head over "Google Settings" in your device and search for related functionalities.
If you have any question related to your personal privacy that may stop you from using AutoBluetooth, please write to fanciullimassimiliano at outlook.it for clarification.