Arduino has been most popular microcontroller platfrom for programmers. There has been new addition of wifi based dirt cheap ESP8266. Both provides quick and easy way to create IoT applications.
Sample IoT application will be created on the spot using Arduino and ESP8266. You will be able to control LED attached to Arduino via your phone. Few sets of Arduino, ESP8266 and required components will be arranged for attendees. If you have these boards, you can bring them and work on them. Bring laptop if you want to do programming on your laptop.