Maybe Polar [0] would suit your needs, I have no idea how it does with TTS. I'm assuming by native you mean "runs on your hardware not a web app". It's native for desktop OSes, not for mobile and they have a syncing service between your devices.
On my iPad I've long been a fan of GoodReader, again I've never tried TTS with it.
[0] http://getpolarized.io/