This is an AR app developed in Unity, using AR Foundation.
https://docs.unity3d.com/Packages/com.unity.xr.arfoundation@4.1/manual/index.html
When you start the app, the camera detects a flat surface, and when you tap the screen, you can place Unity-chan in that location.It is designed for iOS and Android applications.
AR Foundationでユニティちゃん召喚スマホアプリを作ってみた - Synamon’s Engineer blog
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