@Hussy,
I had no issues at all accessing similar Apps that required a Username and Password.
It was Westpac's App only.
The problem began about 1 week into my 5 week holiday.
I travelled to London, Crete and Cyprus.
The problem persisted when I arrived home so I deleted the App and reinstalled it. It has not been the same since. It is extremely slow to load, if at all.
It's now at the stage where I can't trust it if I need to buy or sell.
Hopefully it's not widespread, but it's certainly impacted me.
Worst case scenario you can log into their website and use that, but it's not user friendly on a mobile phone.
Good luck nonetheless.
(20min delay)