When I try to open the Minecraft app it gets as far as the white screen with the Mojang logo on it and crashes out back to my home screen.  This has been happening since Friday 7th February.  I have tried restarting my phone, restarting the app etc etc.

The issue started when I was looking at my Xbox live account trying to change my gamer tag.  After that I couldn't get in to the app on my iPhone.