I have never seen it missing. Have you created any blogs in the past or would this be your first? Did you try scrolling the window a little to see if maybe the + was just not displaying at first? You might try restarting your phone to see if that helps. Let me know if the issue continues.
"I am only one, but I am one. I cannot do everything, but I can do something. And I will not let what I cannot do interfere with what I can do." Edward Everett Hale