You do not have to sign up every month, because if Google catches you (what they will do), your application will be permanently deleted and itβs not allowed to be flagged.
Add Subscriptions and Recurring Payments
With subscriptions, you can add products that charge for content or services on a regular basis. You can offer multiple subscribers in the same application.
To add recurring payments and a subscription to your apps, you'll need to use the Google Play In-app billing API.
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