The Amazon Dash button, it’s all the buzz lately. Regardless whether you think it is the greatest invention or just a passing fad, it is a nice little IoT device. There is already work underway to try and make it work with custom code.
This is where the up and coming ESP8266 mcu can shine. For under $3 you can have a wifi chip plus a programable micro-controller. You just need to add a cheap button (like the Staples Easy Button for around $7.) Add good ol’ IFTTT Maker Channel and you will be set to go with your custom IoT button for about $10.
Check my hackster.io project (https://www.hackster.io/noelportugal/esp8266-ifttt-easy-button) to learn how to make your own.