AppMySite is based on a subscription model. Once you stop paying for your subscription, your mobile app will automatically be deactivated, even if it is live on Google Play and App Store.
Your app will be moved to the Preview plan and will be saved in your account. Your apps will become functional again after updating your payment details.
If your app is already published on the app stores, the app listings will not be removed in case you stop paying for the subscription. However, the app itself will be blank in case someone downloads it from the app stores.