Yes, I would say 'spend time doing something' is an English idiom. For example, I spent time watching the ships, I love to spend time reading with a coffee, we used to spend time together in Scotland.

Hello! "glued to sth" is an idiom that means that somebody is attached to something else and can't quite leave it. In this case the phrase refers to people's addiction to technology and how this has a negative impact in people's lives. I hope to have helped you!