Well, MewSeek is like limewire and, if you get the paid version, you can add songs to the ipod/music app. And Wifi sync lets you do just that, sync over wifi (but sadly not bluetooth)
The guy who made MewSeek threatens to shut it down because there were cracked versions. You can get MewSeek pro for free still..
btw, mewseek pro songs have muffled sounds in the background sometimes and it hurts my ears..
I just use frostwire for my songs.. They are better quality mp3 files