iPhone Local TTS EPUB Reading - Audiobookify

I've been working on this project (been a developer for a few years) for a few months now, and it has been in active testing for ~2 months. Its an EPUB reader that also offers local offline TTS, so its not just TTS focused, its meant to be a good regular reading app as well. I'd like to think it currently has the best TTS implementation of any app on the app store right now though.

Essentially the main focus is efficiency. I'm aiming for the best battery life, balanced with quality of narration. Models for now are Kokoro and Supertonic 3(RIP), both of which have been hand optimized for iPhone (so my own coreML conversions and optimizations of these models). The result is great thermals, great battery efficiency (and its free).

I plan to add more models in the future, but honestly small TTS models that work well on mobile are scarce. I'm working on a conversion for models from Kyuutai next, but its a lot of work to get it working well.

You can find some previous feedback from a much older build (many updates since then) Here

Some downsides:

- No PDF support for now.

- Still needs testing, especially for older iPhone models.

- Not open sourced for now.

Testflight link: Join the beta

You can get a feel for the narration from the video, it was recorded entirely on device (Kokoro, Heart).