Blackr app does not collect any personal user data.
It requires the following special permissions to function:
Draw over other apps - in order to draw black screen simulating off screen on OLED devices.
Run at startup - to start the service if the app was running before shutting down.
Phone State - if a call is incoming, switch off black screen.
In app purchases - to support developers by buying pro features.
No internet permission requested by app and thus, no user data is collected by the app itself.
Designed taking absolute user privacy in mind. Enjoy without any worries!