Free and Open Source Software

Hello everyone! I am interested in replacing the Google Speech Recognition and Synthesis app on Android. For Speech-to-Text (STT), I've tried Whisper and FUTO, and settled on the latter because it seemed to be more versatile. Also, FUTO seems to have some decent recognition, but not yet capable of handling all the languages that I want. Regardless, so far happy with STT. The only annoyance I have is that it does not appear as an option in the settings for Speech recognition :(

However, I can't seem to find any replacements that have good Text-to-Speech (TTS) quality. I tried espeak-ng and RHVoice, but both have robotic outputs.

Given the recent advancements in AI, I was expecting that there would be ways to incorporate open source TTS models like Kokoro to generate speech on the go. Nevertheless, I could not really find any such apps so far.

Has anyone managed to completely replace the Google app with (an)other privacy-focused FOSS app(s)?