By far my most favorite use is as a notepad that I always have with me. I use a custom keyboard to make typing faster and more accurate.
Anything y’all like to do with your phones that you feel like most people miss out on?
Automation. My phone automatically triggers API calls, settings tweaks, launches apps to specific pages/playlists, and collects usage statistics to a local and private location all on its own. This means I only get a day and a half of battery life, but the tradeoff is well worth it in my opinion.