The accessibility bit was great too. I mostly make internal work sites so the emphasis isn’t so much but by being ‘forced’ to do it to complete a tutorial meant that I saw how easy it was and then stumbled upon the colour blind emulation in chrome which I’ll definitely use in future and big-up at work.
I’ve been trying to think of ideas. Most involve external things like material UI or rxjs that people rave about but I haven’t got around to using. One more native web thing would be something fun with the webcam API. Or something more advanced like webgl, web workers or indexed dB. But again it’s just laziness or lack of time that means I haven’t played with them yet. And it might be hard to make a fun tutorial for them.
By the way I used the popout panel from your react book / tutorial for something at work 2 years ago and still going strong 
. My css usually needs inspiration like that
