Small tab bar height with sliding bar under the flip board in SWIFT or OBJECTIVE-C

Question

Small tab bar height with sliding bar under the flip board in SWIFT or OBJECTIVE-C

How can we simulate a tab bar in a Flipboard application? It has a lower height compared to the default tab strip height specified when embedding the view in the tab bar controller. I know that there is a function for the height of the tab bar, but what confuses me about the application’s tab bar for flip boards is the thin RED bar under the tab bar icons, which slides over the tab bar and stops under the pressed icon.

I was able to simulate it using 1 ViewController, with ScrollView to change scenes (view controllers are added as subzones inside ScrollView) and UIView as TAB BAR. Thus, animation can easily happen.

Here's how I managed to imitate.