I can’t recommend another excellent free ebook enough: Zen of Palm. It accurately describes the key differences between designing for desktop and mobile, which

I can’t recommend another excellent free ebook enough: Zen of Palm. It accurately describes the key differences between designing for desktop and mobile, which explains why PalmOS was so much easier to use than the various Windows-based mobile formats from Microsoft at the time. I even wrote a whole blog series about this book two decades ago (https://dingyu.me/blog/zen-of-palm-1 https://dingyu.me/blog/zen-of-palm-1). I switched from a Dell Pocket PC to a Treo 650, and it was such a revelation. IMHO, this little phone is still one of the best in terms of simplicity, even today.