It works both vertically and horizontally. You just turn it.
Yeah, the battery isn't so great for long flights. I've been lucky. Several flights have had plugs so I just use the wall charger. My last 3 flights were on Virgin America which has both plugs and USB ports to use for charging.
Sadly, I also usually carry an extra battery with me. I've been looking for a "super battery" for a while, but I don't think anyone has made one yet.