An audit is a calculation of all the city's stats in the Main Menu (money, income, population, etc., which can all be seen on the Side Bar.) Before the Optimization Update, audits had to be calculated manually from the Town Hall, and this took roughly 20 seconds. After the update, audits were automatically calculated at the end of each Month and this took a whopping 0.667 seconds. This completely replaced the manual audit button.
Gallery[]
The audit button, next to the Build Token Return button. These have now replaced by the Government Grant and One Time Tax Levy buttons