Thanks for pointing that out. We recently did a major overhaul of the Mobile guide and moved some stuff around, and there are still some ghost pages floating around that shouldn't be up there but haven't been purged. Any page that belongs to the guide is available through the sidebar TOC, and should display normally. I'll look into nuking old assets that shouldn't be around there any more.
But, in the spirit of Halloween, these phantom pages wander the Developer Site after their death, sewing terror and confusion among the living.