1.  The Dice App does not seem to be outright restricted from tournament play, although it is not approved.  The answer seems obvious to me, but may not be for others.

2.  I wouldn't prefer to use the app in anything other than friendly games, because handing my iPhone or iPad to another player doesn't fit my precautionary side with my expensive electronics.  Yet, another player may not mind. 

 My biggest issue with the dice app is the price! Maybe if I played the RPG I could justify the $5 price tag. 

Plus, I just like rolling dice!

 I realize this information comes too late for Worlds, but I did receive a response to this question:

"The Star Wars dice app is legal for tournament play.  The device running the app must be used on the playing surface in full view of both players."

Hey, that's really good to know. I have a related question: do you need to have more dice than those included in the Core Set in order to play in a tournament? Currently I only own 3 agility dice and 3 attack dice, but the tournament rules say, "Each player must bring an X-Wing core set and any additional components he needs for his squad. This includes but is not limited to dice…" (emphasis added). So will I be disqualified if I just bring my measley 6 dice that came with the core set?