it's way too fucking laggy, doesn't even work on iphone 4s.
Why the hell does a chat application need that much RAM?
it's just strings of text.
I have an iPhone 5S and it's laggy as fuck/crashes for me as well.
The reason for the lag is that it's actually a stripped down version of the HTML5 RS client. Not sure why they went for that, it would be a much nicer user experience if it was a native iOS/Android app. It's not as if Jagex don't have experience with iOS in particular (they have a few games on the App Store, although admittedly they haven't been updated in ages).