Smartphone AR apps are usually based on image recognition, object recognition and geo position. But things like movements, audio, thermography and color recognition can also be triggers for AR. They mainly use the camera of the mobile device to “add” virtual content into the given environment.
But sometimes it’s all about web-based Augmented Reality (webAR) therefore, users don’t even need an app. A simple click on a link or the scan of a QR-Code offer the same options – it could not be more convenient.