Tipler does not collect or transmit any information about you. It does not track when you use it, how you use it, where you are when you use it, what kind of device you have, or anything else really.
It's just a calculator. It does nothing other than calculate tips.
Note that if you permit it, Apple will collect usage data including crash reports for the purposes of fixing bugs and tracking downloads and sales. Tipler collects no information of it's own, however.