Axure

This tool can do math. You can have dynamic content and conditional logic. You can move content between pages and can do animations and transitions almost like everybody else.

A prototyping tool that can not do basic math or conditional logic is not an efficient prototyping tool. With Axure, I don't have to explain the user journey, it works like a real website or app and my clients can move and share the link as well as check the same prototype on multiple devices. The best part for this is the great community that will help you learn and handle the tool.