Text to Speech (TTS) appears to require an active internet connection to be able to use. Testing on GrapheneOS, there doesn’t appear to be an option to use your local TTS engine, only their network-dependent TTS. If I disable network permission, TTS does not work.
Reading and understanding the code is outside my wheelhouse. But right now, I am concerned about the TTS feature and other third-party integrations where there is currently no alternative option that is more privacy respecting.
Their privacy policy states that
Readest may integrate with third-party services, such as dictionary lookups or cloud storage providers (e.g., WebDAV). We ensure these integrations respect your privacy, and we do not share your data with them beyond what is necessary for the requested functionality.
For functionality, wouldn’t that still mean they’re sending the contents of what you read to to the third-party TTS service? The same goes for their other third-party integrations like dictionary lookups and translation service.
I don’t like this. Many of these types of tools already have local alternatives without requiring you to share your data with a third-party. I’m using SherpaTTS from F-Droid, for example, which allows me to download a high quality TTS voice for system use. Other Android E-Readers I’ve used in the past supported it including Librera, ReadEra, etc. These other e-readers functioned just fine without network permission.
An e-reader of all things should be able to function without active internet, both from privacy and usability standpoints.
I’m also having a hard time understanding the difference between their Play Store version and github release.
Equally concerning is this Github issue that indicates a strong dependence on Google services for the Play Store version, but not the GitHub version without proper explanation.
Readest also seems to be struggling with F-Droid release due to not complying with inclusion criteria. I don’t usually install apps from F-Droid directly, but having an app listed there does provide some reassurance for me.