. . . then you should probably check out SeatGuru.com. The site provides you with information about the best seats in the plane as far as leg room, view of the video screen, and space, which seats to avoid, and other useful information about power outlet locations, seat pitch, etc. It's very simple to use the site: simply look at your airline ticket confirmation, select the carrier from the menu on the site, select the type of plane from the carrier list, and mouseover the seat you have been assigned to receive information.
I'm definitely going to use this the next time I'm checking in at a kiosk or printing my boarding pass at home from my computer. I would imagine that you could probably access this site from any smartphone with a bowser, but I haven't tried it myself.