Meeting Auto Dialer app on the Android playstore requests access to your contacts. The app does not send the contacts on the network and uses it only for dialing into meetings/calls. A copy of the contact is stored in the local database on the Android phone and it is encrypted locally on your phone. The information stored by meeting auto dialer – contacts, meeting numbers, passcodes, last date of use, custom templates may be backed by Google’s backup service on Android Marshmallow and above.
The app is supposed to help you dial into your meetings quickly and therefore save you time. The developer of the app in no way gets access to your private information stored in the app and that will not be changing in the future. Enjoy the app.