Are you reading your tweets bottom-up or top-down?

I use TweetBot on the iPhone and read from where I last left off scrolling upwards. If it has been a prolonged period of time, I will just scroll to the top and just read downwards a bit because I have realized there is never too much that I actually miss that isn't repeated.

Sidenote, not sure why poster takes so long, "5min" to scroll to the top when all that is necessary in most iPhone apps to scroll to the top is tapping the black bar at the top of the screen.