Brew Pal Carbonation

I'm not sure if anyone is familiar with the Brew Pal app. I bought it a few weeks ago and i LOVE it! Anyways, since this isnt a commercial for Brew Pal, i'll move forward with my question... In the app, under the 'Carbonation' section, it lists the keg pressure you should use. My question is, what exactly is that for? Is that the serving pressure or the force carbonating pressure? You can change the temperature in which the beer is stored at, which affects the keg pressure numbers. For instance, under American Pale Ale, it says if the beer is at 65F, to use 21.4-30.5psi, and when i switch it to 42F, it changes it to 10.0-16.7psi.
My method of force carbonating has always been to pump it up to around 30psi and leave it for a few days, shaking the keg around periodically.
Any ideas?

The pressures given are for serving, or carbing using the set and forget method.