Everyone I know in the world of tabletop RPGs says that people shouldn't use their smartphones at the gaming table. It's a point of pride or virtue signaling that our hobby is one that eschews such a vulgar and ubiquitous habit.
I agree with the sentiment: Be Here Now, play face-up, and enjoy your friends. But allow me to express a heterodox opinion: phones are useful at the table!
The number one reason I use my phone is to conduct conversations with players in languages not everyone knows. If we're talking in Giant or Sylvan, we do it in text messages.
We use texting as a substitute for passing notes. Invaluable!
I have the Google Drive app on mine. It lets me reference a few key documents that I rarely need such as a list of diseases or random Elf place names. A random name generator website helps to name new PCs and NPCs.
We all want to be man-nerds and add up treasure and XP in our heads. But there is nothing wrong with using the calculator function. Calculating areas and volumes is much easier with the calculator too.
So talk to pretty girls or get your sports scores later, but don't ditch the cell phone at the table!