Looking at where the 10 wealthiest billionaires in the world attended for undergrad is a poor way to choose a college. All of the under 30 billionaires in the world attended Stanford for undergrad and developed their app while students, but the sample size is too small to be meaningful, like with your list. An article discussing why Stanford produces a large number of tech billionaires with examples is at http://www.independent.co.uk/student/news/the-billionaire-factory-why-stanford-university-produces-so-many-celebrated-web-entrepreneurs-8706573.html .