I would like to add applause at the end of my last song on the playlist. There is an option to add soundeffects at the end of every song except the last son on the playlist. Does anyone know how to do this? Thanks!

I don't know if there is an "official" way to do this in Express, but one work-around that springs immediately to mind is this:

Find a very short track to place at the end (e.g., AFTER your current last track where you want the applause effect), and set the volume to "mute" (e.g. volume marker all the way down to the bottom.)

Now the the song you want to have the applause effect applied to is no longer the last song, so the effect should be enabled.