A robot car using a raspberry pi pico w, controlled by an iphone app.
Iphone app is based on this tutorial: https://www.freecodecamp.org/news/ultimate-how-to-bluetooth-swift-with-hardware-in-20-minutes/
Pi pico W app is based on these examples: https://electrocredible.com/raspberry-pi-pico-w-bluetooth-ble-micropython/