Some callers deserve a VIP status, that's why Nagish has a favorites tab - So you can quickly find the contacts you care about.
To add a contact to your favorites tab:
Tap on contacts (at the bottom of the screen)
Tap Favorites on the top
Tap the + button on the top left corner
Then tap "Add a favorite"
Choose your desired contact
That's it!
To remove a contact from your favorites, simply swipe over it with your finger from right to left or tap 'edit' on the top right corner of your screen.