For my own future reference, here’s a list of all available UIFont Family names in iOS 8:
Academy Engraved LET
Al Nile
American Typewriter
Apple Color Emoji
Apple SD Gothic Neo
Arial
Arial Hebrew
Arial Rounded MT Bold
Avenir
Avenir Next
Avenir Next Condensed
Bangla Sangam MN
Baskerville
Bodoni 72
Bodoni 72 Oldstyle
Bodoni 72 Smallcaps
Bodoni Ornaments
Bradley Hand
Chalkboard SE
Chalkduster
Cochin
Copperplate
Courier
Courier New
DIN Alternate
DIN Condensed
Damascus
Devanagari Sangam MN
Didot
Euphemia UCAS
Farah
Futura
Geeza Pro
Georgia
Gill Sans
Gujarati Sangam MN
Gurmukhi MN
Heiti SC
Heiti TC
Helvetica
Helvetica Neue
Hiragino Kaku Gothic ProN
Hiragino Mincho ProN
Hoefler Text
Iowan Old Style
Kailasa
Kannada Sangam MN
Khmer Sangam MN
Kohinoor Devanagari
Lao Sangam MN
Malayalam Sangam MN
Marion
Marker Felt
Menlo
Mishafi
Noteworthy
Optima
Oriya Sangam MN
Palatino
Papyrus
Party LET
Savoye LET
Sinhala Sangam MN
Snell Roundhand
Superclarendon
Symbol
Tamil Sangam MN
Telugu Sangam MN
Thonburi
Times New Roman
Trebuchet MS
Verdana
Zapf Dingbats
Zapfino