Easiest feature in the world to implement.
I wanted to download a 6.5mb PDF from cloud, tried the inbuilt preview feature- file too large. So lets open it in goodreader I thought. No can do- there is no 'open in' feature. Every other cloud service I've used on iOS has this feature, it beggars belief that BT wouldn't bother with it. It would take all of five minutes to implement and would improve the usefulness of the cloud service immensely.