I am currently evaluating ext JS 4 specifically for creating client side line and column charts on a mobile webkit browser (iPad Safari). Today I just noticed that you have a beta for touch charts. Is this a different product? If so would I still need ext JS 4 and if not should I switch over to this new library for my evaluation?
Because Sencha Touch was built specifically for the mobile web, it seems like the natural choice for your application. Touch Charts are a drop in addition to Sencha Touch designed specifically to run on these devices as well and are optimized for just that job. We do plan to harness the enhancements made to our charting package as a result of developing Touch Charts in our desktop product as well.