# Documentation about implementing in-app purchases on mobile (Android, iOS) and creating custom components

**URL:** <https://forum.castle-engine.io/t/documentation-about-implementing-in-app-purchases-on-mobile-android-ios-and-creating-custom-components/414>\
**Category:** News\
**Created:** [August 29, 2021, 2:22am UTC](https://forum.castle-engine.io/t/documentation-about-implementing-in-app-purchases-on-mobile-android-ios-and-creating-custom-components/414 "2021-08-29T02:22:34Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![michalis](https://forum.castle-engine.io/user_avatar/forum.castle-engine.io/michalis/32/3_2.png) [@michalis](https://forum.castle-engine.io/u/michalis)\
**Post date:** [August 29, 2021, 2:22am UTC](https://forum.castle-engine.io/t/documentation-about-implementing-in-app-purchases-on-mobile-android-ios-and-creating-custom-components/414/1 "2021-08-29T02:22:34Z")

</div>

| [![In-app purchase question (in Polish)](https://castle-engine.io/wp/wp-content/uploads/2017/12/iap_1-200x356.png)](https://castle-engine.io/wp/wp-content/uploads/2017/12/iap_1.png "In-app purchase question (in Polish)") |

I have documented how to implement in-app purchases on mobile (Android and iOS) on [In-app purchases (wiki page)](https://github.com/castle-engine/castle-engine/wiki/In-app-purchases). This is a much updated and extended version of what was previously in the [TInAppPurchases](https://castle-engine.io/apidoc-unstable/html/CastleInAppPurchases.TInAppPurchases.html) class API docs.

(A complete example showing this will follow later too.)

Another new useful documentation page is [how to create custom components](https://github.com/castle-engine/castle-engine/wiki/Custom-Components). For this, the primary example is in [examples/advanced\_editor](https://github.com/castle-engine/castle-engine/tree/master/examples/advanced_editor).