If you are facing a situation wherein you see two app charges showing on your bill, then that will be totally concerning. However, most of the time, this is not an issue, but an expected behavior.
Please take a look at the screenshot below.
As you can see, there are two charges for the BoxBuilder app in this invoice. However, looking at the app history in the backend, we find that there were actions done by the store that triggered the charges.
On 08-29-2023, the merchant installed the app and was charged $24.99.
On 09-12-2023, the merchant uninstalled the app, and again on the next day, 09-13-2023, reinstalled it, which started a new subscription, with a charge of $24.99.
Please note that the BoxBuilder app offers a 7-day free trial.
Based on information from the Shopify Partner Support team, customers may experience a double charge due to overlapping subscription cycles. This occurs when a customer initiates a subscription, cancels it, and then begins a new subscription, resulting in the overlap and subsequent double billing.