Go With Them
It is rare these days that a teen will want to hang out with their mom or dad, but throw this game in the mix and BAM! You can spend some quality time together hunting Pokémon and battling at gyms.
Just make a point of offering to go for walks with your teen so you can both hunt for your local Snorlax (still haven’t caught mine) and find Pokéstops. This can be a great time to have some chats about what’s going on in their lives, sex, why the sky is blue, etc.