You can link Ultimate To-Do List with either a Google or Toodledo account. When you do this, your tasks appear on one of these web sites, so you can access them from a web browser on your desktop or laptop computer.
Or, you can download an Android emulator such as BlueStacks or Andy to run Ultimate To-Do List directly on your Windows or Mac computer. An advantage of doing this is that you can access your tasks even when you don't have an internet connection.
The app will give you the option of establishing a link to an account when you first run it. Or, if you already have tasks that are not linked, you can go to the “Account Management” area within the app’s settings to establish the link.