The app doesn’t access any user data or data of other apps. It only requires one permission in devices with Android M or later versions ( i.e. Do not disturb access) as silent mode can only be used with this permission on later OS versions. 

Ads follow all the policies provided by google and the country rules in which app is released. No data collection or background process initiated by app without user consent.

App will never ask for any kind of donation or money without proper in-app purchase legalised by google. Neither app asks for any type of user credentials for using the app.