I was recently troubled with a web application crashing on older iOS devices without an obvious cause. We were loading a page with several tiles of content, and it would either crash as the page loaded or if you happen to scroll down the page too quickly.
Then as another test, I cut out all our CSS, and the crashing issue stopped! After some hunting through our stylesheets, I landed on this:
This was sitting at the top level to deal with a transition flickering
issue seen in some Webkit browsers (but mostly just native Android), and
it turns out to be a memory hog. We’ve gone forth without the
-webkit-backface-visibility rule so that iOS users won’t suddenly blow
up with memory problems, and for now our native Android browser users
will have to experience some flickering.