If you visit any of the Cafes in any Pokemon Center in Alola and purchase a drink, you will be given a free Healing item, depending on the day of the week, from another region:
Monday - Lumiose Galette - Kalos Region
Tuesday - Rage Candy Bar - Johto Region
Wednesday - Casteliacone - Unova Region
Thursday - Old Gateau - Sinnoh Region
Friday - Shalour Sable - Kalos Region
Saturday - Lava Cookie - Hoenn Region
Sunday - Sweet Heart - Unova Region