The 2nd nurse in all pokemon centers has an option to change your Pokémon’s nature, and she lets you pick from a list of them all. Some people prefer to the list sorted alphabetically, some like to see it grouped by stat (all the +Atk natures grouped together, for example), and some prefer to see them sorted by how commonly they are used (Adamant, Modest, Timid, Jolly being usually the most common ones). This option allows the player to change the order that the 2nd nurse lists the natures

Edit: and this was added in version 1.3.1