Designing smart things, so as to ideate and program them, is a complex process and an empowerment opportunity. Toolkits can help non-experts engage in their design, that is, in their ideation and programming. This paper presents the IoTgo toolkit, made of card-based material and digital components. Playing with IoTgo can help understand the design context, ideate smart things for it, make them communicate and program them with patterns. In recent years, IoTgo was used and evolved at a distance with few participants. This paper presents a study with it, for the first time in presence, in a high-school. Results are discussed and suggest what role IoTgo or similar toolkits can play in the rapid design of smart things with non-seasoned designers or programmers.