Since I live in the US and was buying tickets for the London show, I couldn't use the app. It limited me to US dates (and Vancouver for some odd reason) only. Bummer as I was only able to get one ticket through the pre-sale online and needed four.
Went to buy tickets for the London show this morning (started at 4 am East Coast US time to hit the start of the pre-sale) and had no luck until 5:25 when I got a single GA ticket (I was trying to get 2 or 4 up to that point). I ended up buying that one and the rest on StubHub at 2.5x the price. Certainly not the mods' fault but I won't be renewing my membership again. I had the same issue on the IE tour in NYC. It saddens me to say it but I'll just skip the shows or buy my tix off StubHub and avoid the headache.