Why is my game running so slowly?

I have 5 sprites and some physics. There are a couple events so when planets are pressed gravity is turned on for them and off for the others. I followed the settings on here:

scirra.com/tutorials/298/performance-tips-for-mobile-games

Still, the game runs slow on my Galaxy S3.

Here's the apk file:

dropbox.com/s/q71uhso802pt7t0/Newproject-debug.apk

EDIT:

I used PhoneGap so make the apk file.

It runs slowly because PhoneGap is really slow. Try CocoonJS and it should be fast.