In string theory, one of the many vibrational states of the string corresponds to the graviton, a quantum mechanical particle that carries gravitational force. Thus string theory is a theory of quantum gravity.
Their average web application development cost is around $500K and their staff or contractors' salary is in the six figure plus range. Their proposals are usually based on a lot of fluff with the development rate ranging from $400 - $800 per hour. These types of companies focus on custom development.
Applications developers are software engineers who design games and other programs. According to the BLS, they tended to earn slightly less than hardware and systems software engineers: an average of $44.85 an hour and $93,280 a year as of 2012.