This article explains how to select multiple photos on your iPhone, iPad, or iPod touch.
Starting with iOS 9, Apple changed the way you can select multiple photos. You can now swipe through a bunch of photos instead of tapping them individually, making it easier to share a batch of snapshots with friends and family.
Photos in the iOS Photos app are automatically sorted into collections by year, date, and location. Open the collection you want to select photos from.
Tap Select in the top right corner of the screen.