A Narrow Sea is an interesting read that looks at the connection between Ireland and Scotland, it focuses a lot on Ulster Scots culture and influence. It’s interesting because it’s a collection of 120 short pieces. You might be able to find the original radio episodes it was based on somewhere too.
https://www.amazon.co.uk/Narrow-Sea-Irish-Scottish-Connection-Episodes-ebook/dp/B07HYKF982
Here's a few I've read over the last 18 mnths:
I haven't read A History of Ireland in 100 Words but I remember it doing the rounds on podcasts etc.