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?
Syncthing
It’s a set of apps that help you sync files between devices. It does so without relying on a centralized server, which is a curse (because you need the devices to be on and online) and a blessing (because it can be fast and private). I use it every day. It’s great!