Amazon coins

[wtffgs]

DD Had 400 coins credit when I bought her Kindle Fire. Since then I have downloaded a fair few other free apps and her balance is still showing as 400 coins. I am confused Can anyone enlighten me?

Free apps are free (so long as you steer clear of in app purchases), coins can be used for paid apps.

Sorry, I missed a key bit of information. I let her spend her 400 on crap Sims lifestyle points

Now she still has 400 coins!