You can add a song to your Mocospace Profile by going to your profile page on your smartphone or computer. Once there, go to the music section and click 'edit'.
After that, go to Soundcloud and search for a song that you want to add to your profile, then select it. When you want to change the song you just do the same thing again. Unfortunately it is not possible to add more than one song to your Mocospace profile at one time.
Mocospace can be visited by any phone with a data connection or wifi. Features of the site include gaming, instant chat, e-cards and photos. The site is ad based but there is a paid for version that is ad free for those who find ads annoying.