I need to make voice nicer. I need free or at least cheap application. Android and Windows are acceptable, but better for Ubuntu if possible. I tried Audacity - but couldn't change it enough.
I use Cubase which is good but not cheap. There are GNU projects trying the FOSS equivalent of Cubase that you can look at. Then you can get a plugin and many effects. I think that your question might be better suited for https://sound.stackexchange.com/