How app subscription process works?

[Divy_tatva]

Hello, I'm planning to make a new app but I'm not sure how the subscription process works.

1) As a customer, I received a free trial of one month when I installed the app. I used that app 10 days then uninstalled it and after 2 or 3 months I reinstalled it. Are there still 20 days left in my free trial or is it going to expire?

2) For a paid plan, if I paid 45 dollars for a month, and 20 dollars were used in 10 days, and I uninstalled it, then reinstalled it after a few months, then how will Shopify manage the 25 dollars left over?

Thank you