I had the same blue screen issue on a 5s 64GB (bought Oct 3) when using Keynote and Numbers. Complete PITA as I use my iPhone for business presentations (when the iPad isn't available - this issue didn't occur on the iPad 2 running iOS7) and ended up having to use the company supplied Windows laptop and do the presentations on Excel and PowerPoint with the usual associated connection glitches and lack of polish however the laptop didn't blue screen... how ironic.
I haven't seen any published 'work around' issued by Apple.
Reading through the various forums, I tried the following:
I exported all my iCloud Keynote, Numbers and Pages documents to the iMac downloads folder then deleted all the documents on iCloud. I then dragged the documents from the iMac into iCloud.
The 'new' documents then appeared on the iPhone 5s and now appear to work correctly. Each of the iWork apps no longer show the DONE button (top left) and I can switch between the iWork apps and other apps such as the clock/timer without the iPhone crashing.