flv2mp3.org is now known as flv2mp3.by and it's back to mp3 conversions
Flv2mp3
GitHub - hacksparrow/flv2mp3: Node.js module to convert FLV to MP3 files
FLV2MP3 Converter Apk 1.0.0 Download for Android
GitHub - appelblim/Flv2Mp3: A frontend for ffmpeg written in GTK+-3.0 / C capable of transcribing video files into mp3's of variable quality and setting metadata - this is very basic, it leaks