The icon set is called Voxel, really comprehensive coverage of all the major apps and a bunch of generic ones to fill in the gaps. The font is called player1up, possibly bundled with Zooper since I don't remember searching for a font for this layout. The OS is Android 5.1.1, Sony stock Xperia Z3 ROM. First Android phone I've had where I haven't felt the need to root / install cyanogenmod etc