If you received a bill from either Google Play Store or Apple’s App Store for Glow, you likely your account was likely enrolled in our premium subscription.
Glow users are entitled to try a trial of Glow premium for 14 days. You have to manually cancel the subscription before the end of your trial period, otherwise the account becomes automatically subscribed to our yearly subscription model. Your account will be charged $48 once a year (~$3.99/month *12 months).
If you attempt to enroll in a second premium trial (each Glow account is only entitled to one free trial), your account will automatically become enrolled in the annual premium subscription and will charge your account.
Please note that the Google Play Store/App Store will bill you for the subscription up to 24 hours before the end of your 14 day trial.