Over on GitHub there is a curated list of ARKit projects and resources called Awesome ARKit. ARKit is Apple’s technology to enable augmented reality experiences for Apple devices. In this list you’ll find apps, tutorials, projects, and resources. Some of the tutorials include using ARKit with Metal, importing 3D models for ARKit, building an ARKit application with Unity, and a bunch more. Cool projects include ARSolarPlay, Boxify, ARPaint, cARd, pARtfolio, Measure, Ruler, and more. It’s a great list and I recommend you check it out, especially the list of ARKit apps.