NativeScript/apps/ui/app/bottom-navigation/font-icons-page.xml

<Page class="page">

  <ActionBar title="BottomNavigation font icons" icon="" class="action-bar">
  </ActionBar>

  <BottomNavigation automationText="tabNavigation" >
    <TabStrip>
        <!-- font family + font size + color -->
        <TabStripItem class="special">
            <Label text="All Set"/>
            <Image src="font://&#xF10B;" class="font-awesome font-size" />
        </TabStripItem>

        <!-- default font + valid char code -->
        <TabStripItem>
            <Label text="Invalid Font" />
            <Image src="font://&#xF10B;" />
        </TabStripItem>

        <!-- font family + invalid char code -->
        <TabStripItem>
            <Label text="Invalid Char" />
            <Image src="font://&#xF556;" class="font-awesome font-size"/>
        </TabStripItem>
    </TabStrip>

    <TabContentItem class="special">
        <StackLayout>
            <Label text="char code: phone" />
            <Label text="font: Font Awesome" />
            <Label text="font size: 36" />
            <Label text="icon color inactive: lightgreen" />
            <Label text="icon color active: darkgreen" />
            <Label text="title color inactive: gold" />
            <Label text="title color active: darkgoldenrod" />
        </StackLayout>
    </TabContentItem>

    <TabContentItem>
        <StackLayout>
            <Label text="char code: phone" />
            <Label text="font: default/invalid" />
            <Label text="font size: default" />
            <Label text="icon color inactive: skyblue" />
            <Label text="icon color active: darkblue" />
            <Label text="title color inactive: skyblue" />
            <Label text="title color active: darkblue" />
        </StackLayout>
    </TabContentItem>

    <TabContentItem>
        <StackLayout>
            <Label text="char code: invalid" />
            <Label text="font: Font Awesome" />
            <Label text="font size: 36" />
            <Label text="icon color inactive: skyblue" />
            <Label text="icon color active: darkblue" />
            <Label text="title color inactive: skyblue" />
            <Label text="title color active: darkblue" />
        </StackLayout>
    </TabContentItem>
  </BottomNavigation>
</Page>