I'm looking to develop an AR app for quite some time (about half a decade). We've finally got ARKit and AR SDK to develop with but they are currently available only for the latest devices. In the case of Android apps, it needs Oreo and most of the people will take at least a year to get that. So I'm looking for a way to quickly develop an AR app for Android (and then iOS, but I guess that's easier) that's really accurate and realistic and can run on lower-end devices, such as Redmi Note 3.
PS: If you can suggest any tutorials to help me develop, please do that too.