Good free reverb effect (which works with audacity 1.3) here … https://forum.audacityteam.org/t/good-gverb-settings-for-song-vocals/13355/5
[Moderator note: this is a VST effect for Windows operating systems]
[Trebor note: it is available for Mac OS too: “The DX Reverb Light is the ultimate free reverb plug-in for PC and Mac.” ]