If you download a cookbook app and want to add more recipes, or download a coloring book app and want to add more pictures, you're making what's called an "in-app" purchase.
Apple has made hundreds of millions of dollars on these types of purchases, many of which are made by kids without their parents' permission.
The tech giant must also change billing practices to ensure it has express informed consent from consumers before charging for items sold in mobile apps.
Wednesday the Federal Trade Commission announced a settlement with Apple to the tune of $32.5 million for any unauthorized purchases.
"We believe our settlement provides more robust relief," Chairwoman Edith Ramirez said. "We've alleged in the aggregate that children ran up millions of dollars in charges without their parents' knowledge or consent."
If you're interested in getting a refund for charges you think were unreasonable, contact Apple at 1-800-MY-APPLE.