The rendering of math formulas seems very broken on my iphone. On the main page, math in questions disappears during loading, and sometimes "math processing error" replaces it. On question pages, either the math is displayed in TeX format (which is fine) or "math processing error" appears. I just spent a couple minutes loading and reloading and I never saw math render correctly. When the "math processing error" message appears, the content is unreadable.
For comparison, the math on question pages renders fine on my iphone on mathoverflow.