Very impressive how the almost the entire application is written in lua(JIT). Particularly impressive how it is fast enough to do CPU blitting/blending[0]
I wonder why is lua so rarely utilized like this on its own. Such a neat language.
[0]: https://github.com/koreader/koreader-base/blob/master/ffi/bl...
Running on my Pixel 6a, I wouldn't really characterize it as super responsive. This context, I think, helps me understand why.
Very snappy on my Pixel 4a. Not sure what's causing the performance problems on your phone.