This was discussed at http://wordpress.org/support/topic/plugin-wp-super-cache-different-cache-files-for-different-mobile-devices and you gave an answer about using filters. That's fine if you want to be a hardcore WordPress developer but if you're an end-user then that answer was worse than useless because you've given an answer and then nailed it to the wall well out of reach of the average user. I've been maintaining my WordPress installation for a few years but I couldn't readily find any useful info about where to create or modify the cached_mobile_groups filter.
Is there a simple way I can specify the groups array so that wpTouch and wp-super-cache serve different cached pages for iPhone & iPad without having to wade through the docs?
Does it go in Functions.php?
Does it go in wpTouch?
Could you create a settings filed for it?
Is this all to hard for the average user? That kinda narrows your audience. A lot.