The Official EXPO 2020 Dubai App is a very good companion on the EXPO site and helps you plan your visit in advance.
Link EXPO ticket with the APP.
You can upload your ticket here. This is especially handy if you have a multi-day ticket or a Season Pass.
However, it already brings benefits even for a single day ticket.
With the APP you can reserve your Fast-Track, i.e. the faster entrance to the pavilions via "SmartQ".
More info about tickets here
Map of the EXPO site and more info
The app also includes a map to help you find your way around the EXPO site.
There are also tips on the best restaurants, places where you can buy drinks and much more.
Official EXPO 2020 Dubai App for Android and iOS / iPhone
The official EXPO 2020 Dubai APP is available for all Android devices and also iPhones.