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The article doesn't make it clear that the user has to write their own UI script to create the ON and OFF buttons in the Pythonista environment, and link the click actions to the lamp.py script that the author provides. Running that script will producing a missing UI error, and the author provides no hint that the user will have to code this UI themselves. For beginners in Pythonista, this would detract substantially from the usefulness of this otherwise interesting article. That said, if the UI is written, the code and instructions provided work well (except for a missing "GPIO.setmode(GPIO.BCM)" statement in the Raspberry Pi code, and the fact that the static IP instructions provided will not work in the Pi2 onwards).