Facebook - 30min screen, 1.5hr background, 3% Twitter - 3.7hr screen, 32min background, 14% Skype - 1.1hr screen, 35min background, 6% WhatsApp - 1.5hr scree

Facebook - 30min screen, 1.5hr background, 3% Twitter - 3.7hr screen, 32min background, 14% Skype - 1.1hr screen, 35min background, 6% WhatsApp - 1.5hr screen, 4.8hr background, 5% (iPhone 5s)