Charges for apps

It depends on the app developer policy.

If you're talking about "subscriptions", generally you're charged monthly or yearly.

If you're talking about "in-app purchases", I suggest that you contact those apps developer team(s) and ask them.

Regards

Giulio

depend on the app some app are one time purchase only some are a subscription

you can view if you have subscriptions by using this link

If you want to cancel a subscription from Apple - Apple Support