I would like to use an application which is able to blacken my screen (AMOLED) so it consumes nearly no power (of course, while running an app, that cannot be run in the background). The application has other features, too, like proximity sensor driven blackening.
To make the app able to provide all the features, one has to enable it as an accessibility service (e.g. such services are able to lock usage of "Recents" button and so on). Accessibility services can monitor the users interactions and observe what (s)he types. This is a security risk (think of a keylogger).
Looking at the manifest file, the following permissions are required: RECEIVE_BOOT_COMPLETED, VIBRATE, SYSTEM_ALERT_WINDOW, BIND_ACCESSIBILITY_SERVICE, USE_FINGERPRINT, BILLING. My understanding is that given there is no network accessibility, this app (or at least this version) is unable to send user data to anywhere, so it cannot steal anything. Is this right?
Any other related comments are welcome.