II've tried installing and uninstalling the app and I just get stuck On the log in screen
Where are you from??
It could be the region is not compatible.
Have you been able to use the ap prior to this or did you just download the ap? I just got an "ap" update yesterday on my Iphone and there are no issues with it. I think that Apple sends the updates out at different times based on alphabetical or regional- I have family members that will get an update before me- sometimes up to a couple of days.
I had similar problems with my Lumia 920 the first time I installed it. I just kept trying to login and eventually it worked and has been working fine since. So just keep trying.
I find with a hard reset push top and lower button at the same time until it turns off usually works for mine
Same issue I have started a forum here and I invite you to post. If we get everyone together having the same issue hopefully they will release an update that fixes it!