Some lists have an index along the right side.

Find items in an indexed list:
Tap a letter to jump to items starting with that letter. Drag your finger along the index to scroll quickly through the list.

indexed list

Choose an item:
Tap an item in the list.

Depending on the list, tapping an item can do different things—for example, it may open a new list, play a song, open an email, or show someone’s contact information so you can call that person.

Return to a previous list:
Tap the back button in the upper-left corner.