You can add/remove/adjust the "Technical Indicators", etc, but adjusting the "time line", at the bottom (i.e. fine adjust the time range slider) is a little laggy, but do'able. Its best to setup your chart via your yahoo account, and set a bookmark to the sight, with your credentials entered.

So basically, all the "pull down menus work", and work rather quickly, but the time line adjustment is slow. If you just pick one of the presets, 1-day, 5-day, 30-day, 1-year, etc, they draw fairly quickly as well. FWIW, nothing else seems "missing" vs. the PC version.