G'day Jeremy,
I'm happiest using TiddlyDrive with my Chromebook. I would use TiddlyDesktop if I did not have reliable internet access.
My Chromebook has enough oomph to handle Linux (BETA) quite well, so TiddlyDesktop works A-1. Just a pain to setup TiddlyDesktop in Linux, and my Chromebook isn't quite as zippy when all of the Linux "infrastructure" gets turned on by running any Linux app.
If your friend has a Chromebook with ability to turn on Linux (BETA), it does work well if your friend doesn't mind futzing with Linux (and setting up a launcher icon to lauch TiddlyWiki from the Chrome shelf.)
I am no fan of Android apps on my Chromebook, nor a fan of how my Chromebook behaves when Google Play store is turned on. I haven't tried anything Android on my Chromebook for a while, so maybe I'd have fewer complaints today. Then again: I like Android on my phone, but not on my laptop.