What font does GitHub use? The closest font you can get for the GitHub logo is Collegiate font.…
What font does Vodafone use? The closest font you can get for the Vodafone logo is InterFace Std Bold font.
More info here http://www.daltonmaag.com/portfolio/all/vodafone.html
Free alternative fonts for Vodafone logo:
The closest free font you can get is Aller Bold Font.
About free fonts:
Font by Dalton Maag Ltd