11.5% of "free shopping apps sell in-app purchases or subscriptions", that spunned my curiosity.

What could be those apps: - resale/second hand apps that offer boosts to be seen? - apps that sell alert systems when a price is dropping? - grocery/listing apps that sell "no ads" functionalities? - gated brands with VIP things?

Yet, 11.5% looks enormous. I may be old.