How to replace the generic Google TTS service? I kind of hate the voice used for navigation, alarm clock. Seems everything is using that same voice. Too robotic for my liking. I found IVONA Text-to-Speech Voices | TTS Voices | Text To Voice

Not sure how good it is. Is there a better app than Ivona?
Ivona voice sounds the best hands down (especially Amy and the new not yet on Android Salli voice). Works great on all apps for me. Sadly, whenever I reboot phone, Ivona no longer works. Only fix is to reinstall the whole thing which is a total PITA. I still do it though cause it sounds so much better then any of the other choices.