This app was mentioned in 1 comment, with an average of 2.00 upvotes
I second tipsee! I've been using it for a while and so long as you remember to put your tips/hours worked, it's pretty amazing the amount of data it calculates. It basically is an excel sheet but in an easy to use format.
https://play.google.com/store/apps/details?id=com.wcd.tipseepro