I'm a nerd at heart, so I've been quite fond of the three books I've read so far in Susannah Nix's Chemistry Lessons series. Now the fourth title in the series,
Applied Electromagnetism, is $0.99/£0.99 in the US/UK, and it's discountable at Kobo!
Kindle US:
https://www.amazon.com/dp/B07QSSP2JV
Kindle US/Smile:
https://smile.amazon.com/dp/B07QSSP2JV
Kobo US:
https://www.kobo.com/us/en/ebook/app...tromagnetism-1
Kindle UK:
https://www.amazon.co.uk/dp/B07QSSP2JV
Kindle UK/Smile:
https://smile.amazon.co.uk/dp/B07QSSP2JV
Oh, and don't forget the code "partners" which works on this book, since it's discountable. Between my VIP discount and the code, this turned out to be $0.53 at Kobo US...