I really like the app tab feature, and am using it for those sites that I keep open when I am on line (my blogs, my emails, my websites, my calendar). My yahoo mail refuses to open from the app tab after closing the browser and opening it again. I keep myself logged in at yahoo, just as I do for my gmail account. GMail works perfectly every time, opening my inbox right away. Generally, I have to open Yahoo mail in a new tab, unpin the old one, try to re-pin the new one . . . ad infinitum . . . You get the picture? It might be a Yahoo issue, meaning I have to log in from yahoo home every time if I want it as an app tab.