N.E.P.T.R

Not from f-droid, but Piper TTS models are great and performant. You can install the apk and the app requires no permissions. They also have other models other than Piper (eg Coqui). For English, I recommend recommend vits-piper-en_US-lessac-medium for the model.

Here is a link to the list of prebuilt APKs: https://k2-fsa.github.io/sherpa/onnx/tts/apk-engine.html

Here is the Github repo: https://github.com/k2-fsa/sherpa-onnx

Gender is obviously a signed byte.