Who is this "feat." and why is he in so many songs?

Went to Universal Studio Singapore last month & of course I had fun.
It hit me with a twist of L.A mixed with fairy tales & so on. Really want to 
fly to California & Thailand with Derek for summer but my situation is very 
tricky at the moment. I can never find peace when good things come to me but 
who said I'm backing down. Planning to hit Hong kong soon, hoping to 
meet my peers. At the moment I'm resting at home due to my bleeding throat.