Tip percentage calculator and survey. There are many apps on the market that will do a simple calculation for a tip, but what percentage do you leave the server? This application uses a simple, customizable, survey to determine how much you should leave your server. Easily customize each category to your specific desires to ensure that you are confident that what your leaving is the correct amount. Round up or down to the nearest dollar or use no rounding to get the exact amount. Use the calculator by itself if you know what percentage you want to use or use the survey to really be sure that your leaving what you should.