How to place fav bottom center for tabbed iOS tabbed display

I am using this button

//In a Component Page
<ion-content>...</ion-content>
<button fab fab-center fab-bottom primary><ion-icon name="add"></ion-icon></button>

I want it to look like: (without the heart, add a plus sign)

I have tried inside and outside of the template and it seems that putting it elsewhere (such as the tab root .html) would break encapsulation of the component as it only needs to show up in 1 view.

Any idea @keczan ? I just want to find the best way to do it.

Thank you.