Charlie,
I’ve been working on the same thing on my own:
I wrote some code in Python that will change the image on the inkyPHAT approximately every minute, and I’m to the point now where I’m trying to figure out how to wire in the two switches I’ll need (one to shut down the Pi and the second to cut power altogether so the battery can be removed and recharged).
I don’t really understand all the ins-and-outs of wiring up the switches (what pins to use on the GPIO, or how to “ground” the LiPo); this stuff feels a lot harder than it seems when you look things up and people have a tendency to talk to you like you already understand some of the lingo. :)
I’m happy to share my code if it will help your project (it’s really short).
pete