@I am Baas
Once I tested Tray Radio for portability but it didn't look very portable: C:\Users\UserName\AppData\Roaming\Nend Software\Tray Radio\Favorits\favorits_base.rod
I even set up a feature wish list (including a portable version) but never submitted it to the developer. However I have it installed and I will test it more thoroughly before contacting the developer.