Downloading Angry Birds Reloaded requires a subscription to Apple Arcade, which is a subscription service provided by Apple. The service grants access to hundreds of mobile games for a monthly fee. Once you have subscribed to Apple Arcade, you can play hundreds of games whenever you want. There are no IAPs or in-game ads at all. You can check the specific pricing in your area by opening the Apple App Store on your device and tapping the ‘Arcade’ tab. Find out more info here: https://www.apple.com/apple-arcade/