I made a COVID-19 counter with an ESP8266 and an OLED display. It uses WiFi to get JSON objecs from an API, parses them once every 10 minutes and displays the info
Lua for IoT. Geiger counter with NodeMCU. – Igor Pavlovsky
ESP8266 Timer and Ticker Example | Circuits4you.com
ESP8266 WiFi People Counter - Hackster.io
IoT Bidirectional Visitor Counter using ESPP8266 & MQTT