Interesting that pulling your finger up is zooming in while pulling it down is zooming out which I guess is supposed to correspond to "+"/"-" symbols. I would think the opposite is more intuitive which is pulling down is moving the camera down from zoomed out position down closer to the map which enlarges it while pulling up moves the camera back from the map which zooms out.
I think especially if you think in terms of height the functionality makes more sense as it is. Think of an aircraft where pulling the yoke in your direction goes up and pushing it away from you goes down.
