...If you superiors think your time is being wasted at these meetings.

One of the problems with most meetings is that people don't pay attention and make the meeting drag on longer because things need to be repeated.

If your presence is requested at a meeting and you think you don't need to attend get your superior to tell you not to go. If you go, you have a duty (I assume you are being paid, even if only on commission) to pay attention and participate, not to play on your phone.

In my position, I must always carry my phone. Sometimes I must read messages and occasionally take a call even during a meeting. It is always done very discretely, and if I am taking or making a call I will excuse myself from the room. My goal is to participate in the meeting, if I can't I excuse myself and don't disrespect the person leading the meeting or the other participants that are there to do what they are supposed to do.

It is rather egotistical to think that you are wasting your time in a meeting when your superiors, you know the ones that actually pay you, have requested you attend a meeting. You may not get much out of it, but that is for them to decide, not you. There could be legal requirements, or perhaps some information that will make your job easier or communication more thorough.