Although SpriteKit and Touches are living in 0-1-world, you can use UIScreen to report actual dimensions:

2015-09-09 20:29:17.338 AppleTV[1937:53793] <UIScreen: 0x7fd89bd0e740; bounds = {{0, 0}, {1920, 1080}}; mode = <UIScreenMode: 0x7fd89bd0e4d0; size = 1920.000000 x 1080.000000>>

Heading off to bed now with a massive head-cold. Night all.