Over the years my group has thankfully managed to cull anyone who would have detrimentally attached themselves to their phone. We have had our fair share of people though. The person who refused to look up from her Gameboy and stop playing Pokemon without someone prompting her that it was her turn. Who would also them complain because she didn't know what was going on and was confused and bored. The guy who would sit back away from the table with his feet up eating sunflower seeds and reading the sports page, telling us to get him when combat broke out. The guy who was constantly asking other people if they wanted to start up a game of Magic at the table while we were all playing.
On the GM end of things, at least for D&D, I tend to run with a lot of electronic tools. My laptop has really become my DM Screen, and tend to play with spreadsheets, player monitors or projectors, and sound effects. I am also the one usually updating and reprinting players' character sheets and/or cards so there's never a reason for my players to need to use laptops or tablets to keep track of things. One of my players had tried using a combination of tablet and phone for a bit, mostly to try and run combat macros and a die roller; but he ended up abandoning it because he couldn't use it as quickly and effectively as dice.