Changing to glow nurture on kindle

Lori
I just found out I'm pregnant. I got an email to upgrade to glow <a href="https://play.google.com/store/apps/details?id=com.glow.android.nurture">nurture</a> but I can't seem to find a way to upgrade to glow <a href="https://play.google.com/store/apps/details?id=com.glow.android.nurture">nurture</a> on my kindle fire. Is there a way? I want the app on my kindle, not the computer but I'm lost how to get it. Can anyone help?