[ddon]

In my experiments, canvas performance on iOS devices is horrible, and especially with Phonegap... it takes from 100..200 ms to draw a single frame, crazy... Try opening iPad http://funwithhtml5.com/source/reportCanvasBug.html and try to rotate iPad and see how from 1..2 ms per frame it goes to 200ms per frame.

I am playing right now with Ejecta which translates JavaScript to ObjectiveC, and then I get a very good speed, no matter how I rotate the screen.

[city41]

Ejecta doesn't translate to Objective-C, rather the canvas calls get translated to OpenGL.

[Kiro]

I've seen some impressive performance with Ejecta. For an example see Biolab Disaster.