Animate UI Slots with a delay?

Hey! I was wondering how this UI Animation would be done within Unity:
http://s30.postimg.org/rh4sd5txr/boombeach_ui.gif

i am talking about the appearance of the building slots (Landing Craft, Radar, Armory…). so i think i have to animate only one slot, right? but how can i achieve that each slot animation gets played with a delay? and also if i don’t know how much buildings can be there at the end in this menu?

You could have a custom script placed on each tab that has a variable which holds the next tab and a public function that starts the animation on this next tab. Then call this function via Animation Event from the animation.

public class ActivateNextAnimation : MonoBehaviour
{
    public Animator nextTab;

    // enter this as the animation even after some delay in this animation
    public void StartNextTabAnimation()
    {
        if (nextTab != null) nextTab.SetTrigger("Open"); // or whatever your trigger is named...
    }
}

When creating the tabs, just be sure to chain them together correctly and then trigger the very first animation…