'Internet of Things' (IoT) systems are fundamentally changing the way in which we interact and perceive technology. In this paper, we focus on two dimensions of IoT systems; (1) the IoT user interface and (2) the IoT ecosystem. We develop a model that identifies how data is presented to users and how users interact with the system, and the level at which systems interconnect with, and collects data from, external systems. Companies can use the model to map their systems according to the dimensions in order to: (1) identify current state of their systems, (2) identify desired state and (3) better understand the steps necessary to develop more advanced IoT systems. We evaluate the dimensions in five case companies and provide empirical evidence on the transition towards increasingly advanced IoT systems.