Speaker is the person answering questions, User is the person asking the question(s)

Tier 1

Speaker can see queue of questions

User can submit question (and feedback to User that the question was submitted)

User can withdraw his question

User can join the correct event room

User is notified when it is his turn to ask his question

Speaker can delete questions from the queue

Tier 2

User can choose to submit a question via text or audio

There is a spam filter on the submitted questions

Speaker can mute the question

The question being asked is displayed on the projector behind the Speaker

Tier 3

There is autocorrect for questions submitted via text

The User can video chat with the Speaker/Audience (which is displayed on the projector)

The Speaker's phone is also the clicker for the presentation (to avoid the Speaker holding 2 devices)

The User's phone will be automatically silenced when he joins the room