• Let me view and bookmark movie information by pointing at the trailers
• Offer me discount on the soundtrack by scanning my ticket
• Let me order drinks for the break to be brought right to my perfect seat
• Show me other movies I might like and offer discount when I purchase tickets for the same theatre now
• Tel me what soundtrack is playing now
• Present a poll during the break, eg on my guess for the plot.

What app are you thinking about?