Here you can see the sliders to adjust the randomization for each companion pet.
The addon will also make a list of companions you don't have yet. You can mouse over any pet on the list and it will show you where the pet can be obtained. It can also generate a similar listing to help in collecting mounts. You can apply filters to these lists that will remove pets/mounts that are no longer attainable or attainable through certain means such as the card game codes. You can also remove individual pets from the list if you don't want them for one reason or another.
The Collect Me button in the bottom right of your normal companion tab. Here you can see the listing of needed pets.
That's it for this entry, a simple post for a simple but handy addon.