My kw88 is unavailable at the moment with a cracked back but with freedompop, you only need to modify the existing apn to point to http://freedompop.foggmobile.com. I never tried to add a new apn as it wasnt necessary. Open the existing apn and just edit the entry.
More discussion here: https://plus.google.com/115348728328756782496/posts/hXttS5Mt86g
@Paul_Levy Thank you! It works well surprisingly.